Artigos de revistas: "Heterotrophic culture"

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Wang, Jing Han, Hai Zhen Yang e Feng Wang. "Potential of Mixotrophic Cultivation of Chlorella sorokiniana for Biodiesel Production". Advanced Materials Research 779-780 (setembro de 2013): 1509–13. http://dx.doi.org/10.4028/www.scientific.net/amr.779-780.1509.

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Biodiesel from microalgae provides a promising alternative for biofuel production. Microalgal biodiesel can be produced under three major cultivation modes, namely, photoautotrophic, heterotrophic, and mixotrophic cultivation. Studies of biodiesel production from microalgae have been reported mostly focusing on photoautotrophic cultivation, mixotrophic cultivation has rarely been researched. This paper compared the biomass productivity, lipid content, and lipid productivity ofChlorella sorokinianaunder photoautotrophic, heterotrophic, and mixotrophic cultivation. Glucose was adopted as organic carbon source at five concentrations (0.1, 0.5, 1.0, 2.0, 5.0% glucose w/v). Results displayed that microalgal growth was significantly improved in glucose supplied cultures. Synergetic effect of photoautotrophy and heterotrophy existed in mixotrophic cultivation except for 5.0% culture. Highest biomass productivity of 1.178 g·L-1·d-1and highest lipid productivity of 582 mg·L-1·d-1was observed under mixotrophic cultivation with 2.0% (w/v) glucose addition. Lipid content ofC. sorokinianawas mostly higher in stationary phase than in exponential phase. Highest lipid content of 49.37% was observed in 2.0% mixotrophic culture, followed by 47.09% in 2.0% heterotrophic culture.

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Wang, Jing Han, Hai Zhen Yang e Feng Wang. "Mixotrophic Cultivation of Scenedesmus sp. as Biodiesel Feedstock". Advanced Materials Research 777 (setembro de 2013): 268–73. http://dx.doi.org/10.4028/www.scientific.net/amr.777.268.

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Microalgae are a promising feedstock for biodiesel production. Microalgal biodiesel can be obtained under three major cultivation modes, namely, photoautotrophic, heterotrophic, and mixotrophic cultivation. Reported studies of microalgal biodiesel production are mainly based on photoautotrophic cultivation, mixotrophic cultivation has rarely been researched. This paper compared the biomass productivity, lipid content, and lipid productivity of Scenedesmus sp. under photoautotrophic, heterotrophic, and mixotrophic cultivation. Glucose was added as organic carbon source at five concentrations (0.1, 0.5, 1.0, 2.0, 5.0% glucose w/v). Results displayed that microalgal growth was significantly improved in glucose supplied cultures. Synergetic effect of photoautotrophy and heterotrophy existed in all mixotrophic cultures. Highest biomass productivity of 1.307 g·L-1·d-1 and highest lipid productivity of 316 mg·L-1·d-1 was respectively observed under mixotrophic cultivation with 5.0% and 1.0% (w/v) glucose addition. Lipid content of Scenedesmus sp. under mixotrophic cultivation was mostly higher in stationary phase than in exponential phase. Highest lipid content of 27.73% was observed in 1.0% mixotrophic culture, followed by 24.66% in 1.0% heterotrophic culture.

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Wang, Kaixuan, Zhongjie Wang, Yi Ding, Youzhi Yu, Yali Wang, Yahong Geng, Yeguang Li e Xiaobin Wen. "Optimization of Heterotrophic Culture Conditions for the Algae Graesiella emersonii WBG-1 to Produce Proteins". Plants 12, n.º 12 (9 de junho de 2023): 2255. http://dx.doi.org/10.3390/plants12122255.

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The aim of this study was to improve the protein content and yield of heterotrophic microalgal cultivation and establish a simple, economical, and efficient method for microalgal protein production using the novel green alga, Graesiella emersonii WBG-1, which has not been previously reported for heterotrophic cultivation. Through batch heterotrophic cultivation of this alga, we observed that glucose was the optimal carbon source, while it could not use sucrose as a carbon source. Biomass production and protein content were significantly reduced when sodium acetate was used as the carbon source. Compared with nitrate, protein content increased by 93% when urea was used as the nitrogen source. Cultivation temperature had a significant impact on biomass production and protein content. The optimal conditions were glucose as the carbon source at an initial concentration of 10 g/L, urea as the nitrogen source at an initial concentration of 1.62 g/L, and a culture temperature of 35 °C. On the second day of batch cultivation, the highest protein content (66.14%) was achieved, which was significantly higher than that reported in heterotrophic cultures of Chlorella and much higher than that reported for specially established technologies aimed at increasing the protein content, such as two-stage heterotrophic, heterotrophy–dilution–photoinduction, and mixotrophic processes. These results demonstrate the great potential of the heterotrophic cultivation of G. emersonii WBG-1 for protein production.

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Sedlacek, Christopher J., Susanne Nielsen, Kenneth D. Greis, Wendy D. Haffey, Niels Peter Revsbech, Tomislav Ticak, Hendrikus J. Laanbroek e Annette Bollmann. "Effects of Bacterial Community Members on the Proteome of the Ammonia-Oxidizing Bacterium Nitrosomonas sp. Strain Is79". Applied and Environmental Microbiology 82, n.º 15 (27 de maio de 2016): 4776–88. http://dx.doi.org/10.1128/aem.01171-16.

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ABSTRACTMicroorganisms in the environment do not exist as the often-studied pure cultures but as members of complex microbial communities. Characterizing the interactions within microbial communities is essential to understand their function in both natural and engineered environments. In this study, we investigated how the presence of a nitrite-oxidizing bacterium (NOB) and heterotrophic bacteria affect the growth and proteome of the chemolithoautotrophic ammonia-oxidizing bacterium (AOB)Nitrosomonassp. strain Is79. We investigatedNitrosomonassp. Is79 in co-culture withNitrobacter winogradskyi, in co-cultures with selected heterotrophic bacteria, and as a member of the nitrifying enrichment culture G5-7. In batch culture,N. winogradskyiand heterotrophic bacteria had positive effects on the growth ofNitrosomonassp. Is79. An isobaric tag for relative and absolute quantification (iTRAQ) liquid chromatography-tandem mass spectrometry (LC-MS/MS) proteomics approach was used to investigate the effect ofN. winogradskyiand the co-cultured heterotrophic bacteria from G5-7 on the proteome ofNitrosomonassp. Is79. In co-culture withN. winogradskyi, severalNitrosomonassp. Is79 oxidative stress response proteins changed in abundance, with periplasmic proteins increasing and cytoplasmic proteins decreasing in abundance. In the presence of heterotrophic bacteria, the abundance of proteins directly related to the ammonia oxidation pathway increased, while the abundance of proteins related to amino acid synthesis and metabolism decreased. In summary, the proteome ofNitrosomonassp. Is79 was differentially influenced by the presence of eitherN. winogradskyior heterotrophic bacteria. Together,N. winogradskyiand heterotrophic bacteria reduced the oxidative stress forNitrosomonassp. Is79, which resulted in more efficient metabolism.IMPORTANCEAerobic ammonia-oxidizing microorganisms play an important role in the global nitrogen cycle, converting ammonia to nitrite. In their natural environment, they coexist and interact with nitrite oxidizers, which convert nitrite to nitrate, and with heterotrophic microorganisms. The presence of nitrite oxidizers and heterotrophic bacteria has a positive influence on the growth of the ammonia oxidizers. Here, we present a study investigating the effect of nitrite oxidizers and heterotrophic bacteria on the proteome of a selected ammonia oxidizer in a defined culture to elucidate how these two groups improve the performance of the ammonia oxidizer. The results show that the presence of a nitrite oxidizer and heterotrophic bacteria reduced the stress for the ammonia oxidizer and resulted in more efficient energy generation. This study contributes to our understanding of microbe-microbe interactions, in particular between ammonia oxidizers and their neighboring microbial community.

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Correia, Nádia, Hugo Pereira, Peter S. C. Schulze, Monya M. Costa, Gonçalo E. Santo, Inês Guerra, Mafalda Trovão et al. "Heterotrophic and Photoautotrophic Media Optimization Using Response Surface Methodology for the Novel Microalga Chlorococcum amblystomatis". Applied Sciences 13, n.º 4 (6 de fevereiro de 2023): 2089. http://dx.doi.org/10.3390/app13042089.

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The nutritional requirements of novel microalgal strains are key for their effective cultivation and metabolite content. Therefore, the optimization of heterotrophic and photoautotrophic culture media is crucial for novel Chlorococcum amblystomatis growth. Heterotrophic and photoautotrophic biomass samples were characterized to identify the differences between their heterotrophic and photoautotrophic biomass composition and their biotechnological potential. Media optimization through surface response methodology led to 44.9 and 51.2% increments in C. amblystomatis-specific growth rates under heterotrophic and photoautotrophic growth, respectively. This microalga registered high protein content (61.49–73.45% dry weight), with the highest value being observed in the optimized photoautotrophic growth medium. The lipid fraction mainly constituted polyunsaturated fatty acids, ranging from 44.47 to 51.41% for total fatty acids (TFA) in cells under heterotrophy. However, these contents became significantly higher (70.46–72.82% TFA) in cultures cultivated under photoautotrophy. An interesting carotenoids content was achieved in the cultures grown in optimized photoautotrophic medium: 5.84 mg·g−1 β-carotene, 5.27 mg·g−1 lutein, 3.66 mg·g−1 neoxanthin, and 0.75 mg·g−1 violaxanthin. Therefore, C. amblystomatis demonstrated an interesting growth performance and nutritional profile for food supplements and feed products that might contribute to meeting the world’s nutritional demand.

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Cupo, Adelaide, Simone Landi, Salvatore Morra, Genoveffa Nuzzo, Carmela Gallo, Emiliano Manzo, Angelo Fontana e Giuliana d’Ippolito. "Autotrophic vs. Heterotrophic Cultivation of the Marine Diatom Cyclotella cryptica for EPA Production". Marine Drugs 19, n.º 7 (23 de junho de 2021): 355. http://dx.doi.org/10.3390/md19070355.

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Recently, the marketable value of ω-3 fatty acid, particularly eicosapentaenoic acid (EPA), increased considering their health effects for human consumption. Microalgae are considered a valuable and “green” source of EPA alternative to fish oils, but considerable efforts are necessary for their exploitation at an industrial level. Due to the high operation costs of photoautotrophic microalgae cultivation, heterotrophic growth represents a promising economic solution. Marine diatoms are the major ecological producers of ω-3 fatty acids. Few species of diatoms are capable to grow in the dark using organic carbon sources. The marine diatom Cyclotella cryptica was cultivated for 14 days under photoautotrophic and heterotrophic conditions to define the effects on growth parameters, lipid production, total fatty acids and EPA content. Photoautotrophic conditions led to a total EPA production of 1.6% of dry weight, 12.2 mg L−1 culture and productivity of 0.9 mg L−1 day−1. The heterotrophy cultures reported a total EPA production of 2.7% of dry cell weight, 18 mg L−1 culture, a productivity of 1.3 mg L−1 day−1, which are promising values in the prospective of improving culture parameters for the biotechnological exploitation of dark cultivation. C. cryptica could be a potential candidate for the heterotrophic production of EPA, also considering its robustness, capacity to resist to bacterial contaminations and plasticity of lipid metabolism.

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Gao, Yifan, Yuan Li, Yan Yang, Jia Feng, Li Ji e Shulian Xie. "Effects of Trophic Modes on the Lipid Accumulation of Parachlorella kessleri TY". Fermentation 9, n.º 10 (3 de outubro de 2023): 891. http://dx.doi.org/10.3390/fermentation9100891.

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Microalgae are considered to have great potential as a source of biodiesel. Currently, algae culture has three different trophic modes, i.e., autotrophic, heterotrophic, and mixotrophic, but not all kinds of algae are suitable for heterotrophic and mixotrophic cultivation. In this study, Parachlorella kessleri TY, screened from the soil of Shanxi Province, was heterotrophically and mixotrophically treated with glucose as an organic carbon source, and the physiological and biochemical levels of its growth and lipid accumulation were measured. The results showed that the highest biomass and biomass productivity (1.53 g·L−1 and 218.57 mg·L−1d−1) were attained by P. kessleri TY under mixotrophic cultivation. In comparison, the lowest (0.55 g·L−1 and 78.57 mg·L−1d−1) were attained under heterotrophic culture. Furthermore, heterotrophic and mixotrophic conditions could accumulate more lipids (total lipid contents: 39.85% and 42.92%, respectively), especially the neutral lipids. Additionally, the contents of fatty acids suitable for use as biodiesel raw materials in both heterotrophic and mixotrophic cultures increased, especially the content of C18:1. Moreover, due to the lower biomass of heterotrophic cultivation compared with that from mixotrophic cultivation, the total lipid productivity of heterotrophic conditions decreased. In summary, the conditions of mixotrophic cultivation are more conducive to the accumulation of lipids in P. kessleri TY.

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Nishimura, Takao, Raghunath Ramu Pachpande e Tatsuichi Iwamura. "A heterotrophic synchronous culture of Chlorella." Cell Structure and Function 13, n.º 3 (1988): 207–15. http://dx.doi.org/10.1247/csf.13.207.

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Park, Jeong-Eun, Shan Zhang, Thi Hiep Han e Sun-Jin Hwang. "The Contribution Ratio of Autotrophic and Heterotrophic Metabolism during a Mixotrophic Culture of Chlorella sorokiniana". International Journal of Environmental Research and Public Health 18, n.º 3 (2 de fevereiro de 2021): 1353. http://dx.doi.org/10.3390/ijerph18031353.

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The contribution ratio of autotrophic and heterotrophic metabolism in the mixotrophic culture of Chlorella sorokiniana (C. sorokiniana) was investigated. At the early stage of mixotrophic growth (day 0–1), autotrophy contributed over 70% of the total metabolism; however, heterotrophy contributed more than autotrophy after day 1 due to the rapid increase in cell density, which had a shading effect in the photo-bioreactor. Heterotrophy continued to have a higher contribution until the available organic carbon was depleted at which point autotrophy became dominant again. Overall, the increase in algal biomass and light conditions in the photo-bioreactor are important factors in determining the contribution of autotrophy and heterotrophy during a mixotrophic culture.

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Korozi, Evagelina, Vasiliki Tsagou, Io Kefalogianni, Giorgos Markou, Dimitris Antonopoulos, Lambis Chakalis, Yannis Kotzamanis e Iordanis Chatzipavlidis. "Continuous Culture of Auxenochlorella protothecoides on Biodiesel Derived Glycerol under Mixotrophic and Heterotrophic Conditions: Growth Parameters and Biochemical Composition". Microorganisms 10, n.º 3 (28 de fevereiro de 2022): 541. http://dx.doi.org/10.3390/microorganisms10030541.

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As crude glycerol comprises a potential substrate for microalga fermentation and value added products’ biosynthesis, Auxenochlorella protothecoides was grown on it under heterotrophic and mixotrophic conditions and its growth kinetics were evaluated in a continuous system under steady state conditions. Increasing initial glycerol concentration (from 30 to 50 g/L) in the heterotrophic culture led to reduced biomass yield (Yx/S) and productivity (Px), but favored lipid accumulation. Under heterotrophic conditions, the microalga was found to grow better (biomass up to 7.888 g/L) and faster (higher growth rates), the system functioned more effectively (higher Px) and crude glycerol was exploited more efficiently. Heterotrophy also favored proteins synthesis (up to 53%), lipids (up to 9.8%), and carbohydrates (up to 44.6%) accumulation. However, different trophic modes had no significant impact on the consistency of proteins and lipids. Oleic acid was the most abundant fatty acid detected (55–61.2% of the total lipids). The algal biomass contained many essential and non-essential amino acids, especially arginine, glutamic acid, lysine, aspartic acid, leucine, and alanine. In all the experimental trials, the protein contents in the microalgal biomass increased with the increasing dilution rate (D), with a concomitant decrease in the lipids and carbohydrates fractions.

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Puzanskiy, Roman K., Daria A. Romanyuk, Anastasia A. Kirpichnikova, Vladislav V. Yemelyanov e Maria F. Shishova. "Plant Heterotrophic Cultures: No Food, No Growth". Plants 13, n.º 2 (17 de janeiro de 2024): 277. http://dx.doi.org/10.3390/plants13020277.

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Plant cells are capable of uptaking exogenous organic substances. This inherited trait allows the development of heterotrophic cell cultures in various plants. The most common of them are Nicotiana tabacum and Arabidopsis thaliana. Plant cells are widely used in academic studies and as factories for valuable substance production. The repertoire of compounds supporting the heterotrophic growth of plant cells is limited. The best growth of cultures is ensured by oligosaccharides and their cleavage products. Primarily, these are sucrose, raffinose, glucose and fructose. Other molecules such as glycerol, carbonic acids, starch, and mannitol have the ability to support growth occasionally, or in combination with another substrate. Culture growth is accompanied by processes of specialization, such as elongation growth. This determines the pattern of the carbon budget. Culture ageing is closely linked to substrate depletion, changes in medium composition, and cell physiological rearrangements. A lack of substrate leads to starvation, which results in a decrease in physiological activity and the mobilization of resources, and finally in the loss of viability. The cause of the instability of cultivated cells may be the non-optimal metabolism under cultural conditions or the insufficiency of internal regulation.

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Azma, Mojtaba, Rosfarizan Mohamad, Raha Abdul Rahim e Arbakariya B. Ariff. "Improved Protocol for the Preparation of Axenic Culture and Adaptation to Heterotrophic Cultivation". Open Biotechnology Journal 4, n.º 1 (8 de julho de 2010): 36–46. http://dx.doi.org/10.2174/1874070701004010036.

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The effectiveness of various physical and chemical methods for the removal of contaminants from the microalgae, Tetraselmis suecica, culture was investigated. The information obtained was used as the basis for the development of improved protocol for the preparation of axenic culture to be adapted to heterotrophic cultivation. Repeated centrifugation and rinsing effectively removed the free bacterial contaminants from the microalgae culture while sonication helped to loosen up the tightly attached bacterial contaminants on the microalgae cells. Removal of bacterial spores was accomplished using a mixture of two antibiotics, 5 mg/mL vancomycine and 10 mg/mL neomycine. Walne medium formulation with natural seawater was preferred for the enhancement of growth of T. suecica. Adaptation of growth from photoautotrophic to heterotrophic conditions was achieved by the repeated cultivation of photoautotrophic culture with sequential reduction in illumination time, and finally the culture was inoculated into the medium containing 10 g/L glucose, incubated in total darkness to obtain heterotrophic cells. Changes in the morphology and composition of T. suecica cells during the adaptation from photoautotrophic to heterotrophic condition, as examined under Transmission Electron Microscope, were also reported.

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Wu, Kangping, Yilin Fang, Biyuan Hong, Yihui Cai, Honglei Xie, Yunpu Wang, Xian Cui et al. "Enhancement of Carbon Conversion and Value-Added Compound Production in Heterotrophic Chlorella vulgaris Using Sweet Sorghum Extract". Foods 11, n.º 17 (25 de agosto de 2022): 2579. http://dx.doi.org/10.3390/foods11172579.

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High-cost carbon sources are not economical or sustainable for the heterotrophic culture of Chlorella vulgaris. In order to reduce the cost, this study used sweet sorghum extract (SE) and its enzymatic hydrolysate (HSE) as alternative carbon sources for the heterotrophic culture of Chlorella vulgaris. Under the premise of the same total carbon concentration, the value-added product production performance of Chlorella vulgaris cultured in HSE (supplemented with nitrogen sources and minerals) was much better than that in the glucose medium. The conversion rate of the total organic carbon and the utilization rate of the total nitrogen were both improved in the HSE system. The biomass production and productivity using HSE reached 2.51 g/L and 0.42 g/L/d, respectively. The production of proteins and lipids using HSE reached 1.17 and 0.35 g/L, respectively, and the production of chlorophyll-a, carotenoid, and lutein using HSE reached 30.42, 10.99, and 0.88 mg/L, respectively. The medium cost using HSE decreased by 69.61% compared to glucose. This study proves the feasibility and practicability of using HSE as a carbon source for the low-cost heterotrophic culture of Chlorella vulgaris.

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Xiao, Yibo, Xi He, Qi Ma, Yue Lu, Fan Bai, Junbiao Dai e Qingyu Wu. "Photosynthetic Accumulation of Lutein in Auxenochlorella protothecoides after Heterotrophic Growth". Marine Drugs 16, n.º 8 (16 de agosto de 2018): 283. http://dx.doi.org/10.3390/md16080283.

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In order to enhance lutein accumulation and to explain the reasons for the difference in lutein accumulation under photoautotrophic and heterotrophic conditions, different culture modes and the associated transcriptome profiles were investigated in Auxenochlorella protothecoides. The heterotrophic-photoautotrophic transition culture mode was investigated for lutein accumulation, changing from organic carbon to increase biomass in dark fermentation to irradiation under nitrogen rich conditions. This strategy increased the lutein content 10 times along with chloroplast regeneration and little biomass loss in 48 h. The highest lutein productivity and production in the heterotrophic-photoautotrophic transition culture reached 12.36 mg/L/day and 34.13 mg/L respectively within seven days. Furthermore, compared to the photoautotrophic conditions, most genes involved in lutein biosynthesis and photosystem generation were down-regulated during heterotrophic growth. By contrast, two β-ring hydroxylases were transiently upregulated, while violaxanthin de-epoxidase and zeaxanthin epoxidase were mostly downregulated, which explained the extremely low lutein content of heterotrophic cells. Nevertheless, the lutein proportion in total carotenoids reached nearly 100%. This study is the first to our knowledge to report on a comparative transcriptome analysis of lutein biosynthesis, and it provides a promising strategy to boost lutein production in A. protothecoides.

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Fu, Yunlei, Lanbo Yi, Shufang Yang, Xue Lu, Bin Liu, Feng Chen, Junchao Huang, Kawing Cheng, Han Sun e Xiaolei Wu. "Light Induction of Seed Culture Accelerates Lutein Accumulation in Heterotrophic Fermentation of Chlorella protothecoides CS-41". Fermentation 9, n.º 8 (18 de agosto de 2023): 768. http://dx.doi.org/10.3390/fermentation9080768.

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Microalgae are recognized as a promising and valuable source of lutein. However, the current two-stage method for lutein production has drawbacks, such as complex operations and a long cultivation time. Additionally, utilizing heterotrophic fermentation to cultivate microalgae for lutein production leads to low lutein content due to the absence of light. In this study, we proposed a novel cultivation method that involves light induction of the seed culture to enhance lutein production during the heterotrophic cultivation phase of Chlorella protothecoides CS-41. To gain comprehensive insights into the underlying mechanisms of this method, we conducted qualitative and quantitative analyses of specific metabolites related to central carbon metabolism. The results revealed that low-light induction of seeds exhibited higher carbon efficiency compared to cells continuously subjected to heterotrophic cultivation, which may explain the observed increase in biomass and lutein content in cultures. Cultures after low-light induction of seed exhibited significantly higher lutein content (2.71 mg/g), yield (66.49 mg/L) and productivity (8.59 mg/L/d) compared to those consistently cultivated under heterotrophic conditions (2.37 mg/g, 37.45 mg/L, 4.68 mg/L/d). This cultivation strategy effectively enhances lutein yields, reduces production costs and holds the potential for broader application in other algal species for pigment production.

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Khanichaidecha, W., A. Nakaruk, K. Ratananikom, R. Eamrat e F. Kazama. "Heterotrophic nitrification and aerobic denitrification using pure-culture bacteria for wastewater treatment". Journal of Water Reuse and Desalination 9, n.º 1 (9 de fevereiro de 2018): 10–17. http://dx.doi.org/10.2166/wrd.2018.064.

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Abstract Due to the high water demand and unsustainable water resource, wastewater reclamation and wastewater treatment prior to discharge have become current important issues. Various treatment technologies, such as biological processes, have been improved as alternatives. In this study, the biological nitrogen removal system using pure-culture Bacillus licheniformis was developed and used as an internal treatment unit in an aquarium to improve the effluent quality for water reuse. The efficiencies for NH4-N and total nitrogen (TN) removal and the quality of treated water verified the occurrence of heterotrophic nitrification and aerobic denitrification; the nitrification rate was 0.84 mg/L-h and the denitrification rate was 0.62 mg/L-h. The maximal NH4-N and TN removal efficiencies were approximately 73% at the influent NH4-N of 30 mg/L. However, the other competitive heterotroph of Pseudomonas sp. was observed, which resulted in dramatically decreasing efficiencies and an enlarged ratio of carbon consumption and nitrogen removal. Although the overall performance of the B. licheniformis system was lower than the system using mixed-culture nitrifying and heterotrophic denitrifying microorganisms, the advantages of the B. licheniformis system were ease of operation and the fact that it is a land-limited treatment system. The research is ongoing to enhance performance and maintain excellent efficiency in a long-term operation.

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Şentürk, Tuğba. "Effect of different trophic cultures on the amount of total carbohydrate and chlorophyll of Oscillatoria sp." Aquatic Research 7, n.º 3 (2024): 144–54. http://dx.doi.org/10.3153/ar24013.

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Cyanobacteria (blue-green microalgae) is a gram-negative prokaryotic autotroph found in natural waters that plays a pivotal role in biochemical cycles. The present investigation proposed to study the potential of using different concentrations of glucose as the carbon substrate to produce microalgal biomass and biochemical components, such as photosynthetic pigments and total carbohydrates (CH) by Oscillatoria sp. The cyanobacteria were collected, and the isolated colony was found to be Oscillatoria sp., and it was grown in BG-11 medium for mass cultivation. Then, the centrifuged biomass was weighed and used to extract bioactive compounds. Oscillatoria sp. cells were cultured in three different tropic cultures (phototrophic, heterotrophic and mixotrophic) under controlled laboratory conditions with continuous light illumination or unillumination and aeration. Chl–a and total C.H. contents were also evaluated after 120 hrs. The recorded optical density of Oscillatoria was increased from 0.6798 ±0.01 at 660 nm and 0.5847 ±0.01 at 750 nm after 24 hrs to 1.2174±0.002 at 680nm and 1.0243±0.01 at 730nm at the end of 120hrs of the experiment. According to analysis results, the mean amount of Chl-a and Total C.H. of Oscillatoria sp. biomass was determined as 0.5132 µg L-1 and 3.5715 mg mL-1 under the phototrophic culture (absence of glucose), respectively. Under the mixotrophic culture (presence of light), the experimental results showed that the chl-a content was calculated as 0.1770, 0.3380 and 0.7098 µg L-1. In contrast, the total C.H. was calculated as 3.6150, 7.9129 and 11.3191 mg mL-1 in the presence of 2.5, 5 and 10 g L-1 glucose, respectively. Under the heterotrophic culture (absence of light), the results showed that the chl-a content was 0.2366, 0.2456 and 0.2346 µg L-1 while the total C.H. was 4.2969, 8.0990 and 11.5861 mg m L-1 in the presence of 2.5, 5 and 10 g L-1 glucose, respectively. The experimental results showed that the total C.H. content was increased from 3.5715 to 11.58 61 mg mL-1 in the heterotrophic (the absence of light and the presence of 10 g L-1 glucose) BG-11 culture conditions. The chlorophyll-a content was increased from 0.1770 µg L-1 to 0.7098 µg L-1 in the mixotrophic (the presence of glucose and light) BG-11 culture conditions. As a result of the experiment, it was determined that the most suitable culture in terms of total carbohydrate and growth rate was mixotrophic and heterotrophic BG-11 (10 g L-1 glucose) culture condition, and in terms of chl-a was mixotrophic culture (10 g L-1 glucose).

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Blöthe, Marco, e Eric E. Roden. "Composition and Activity of an Autotrophic Fe(II)-Oxidizing, Nitrate-Reducing Enrichment Culture". Applied and Environmental Microbiology 75, n.º 21 (11 de setembro de 2009): 6937–40. http://dx.doi.org/10.1128/aem.01742-09.

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ABSTRACT 16S rRNA gene libraries from the lithoautotrophic Fe(II)-oxidizing, nitrate-reducing enrichment culture described by Straub et al. (K. L. Straub, M. Benz, B. Schink, and F. Widdel, Appl. Environ. Microbiol. 62:1458-1460, 1996) were dominated by a phylotype related (95% 16S rRNA gene homology) to the autotrophic Fe(II) oxidizer Sideroxydans lithotrophicus. The libraries also contained phylotypes related to known heterotrophic nitrate reducers Comamonas badia, Parvibaculum lavamentivorans, and Rhodanobacter thiooxidans. The three heterotrophs were isolated and found to be capable of only partial (12 to 24%) Fe(II) oxidation, suggesting that the Sideroxydans species has primary responsibility for Fe(II) oxidation in the enrichment culture.

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Morowvat, Mohammad H., e Younes Ghasemi. "Maximizing Biomass and Lipid Production in Heterotrophic Culture of Chlorella vulgaris: Techno-Economic Assessment". Recent Patents on Food, Nutrition & Agriculture 10, n.º 2 (18 de setembro de 2019): 115–23. http://dx.doi.org/10.2174/2212798410666180911100034.

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Background: Nowadays, chlorophycean microalgae have attained a broad-spectrum attention as a potential candidate for biomass and bioenergy production. Despite their appreciated benefits, one of major problems is their low biomass and lipid productivity. Here we investigated the heterotrophic culture in shake flasks and stirred tank bioreactor to improve the lipid and biomass production in a naturally isolated strain of Chlorella vulgaris. Methods: A naturally isolated C. vulgaris strain was cultivated in BG-11 medium in shake flask and bioreactor. Its biochemical composition and growth kinetic parameters were investigated. Results: The biomass productivity was improved (3.68 fold) under heterotrophic culture compared to basal autotrophic culture condition in shake flask experiment. The total lipid content increased to 44% of total Dry Cell Weight (DCW) during heterotrophic growth after 21 days. Moreover, a great Fatty Acid Methyl Esters (FAME) yield was observed under heterotrophic cultivation. Total biomass and lipid content of microalgae in bioreactor experiment increased to 4.95 and 2.18 g L-1 respectively, during 5 days of the experiment compared to its basic autotrophic culture. Conclusion: The techno-economic aspects of exploiting C. vulgaris as a biodiesel feedstock werealso evaluated. The results imply that heterotrophic cultivation could compensate the low biomass productivity in microalgae for green energy production. Ever growing rates of established patents on application of various genetic and bioengineering-based methods have made it possible to achieve higher lipid contents with reduced total costs for microalgal biodiesel production as well.

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Singh, V., e A. K. Mittal. "Characterization of biofilm of a rotating biological contactor treating synthetic wastewater". Water Science and Technology 66, n.º 2 (1 de julho de 2012): 429–37. http://dx.doi.org/10.2166/wst.2012.221.

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A four-stage rotating biological contactor (RBC) was designed and operated to treat synthetic wastewater containing 1,000 mg/l chemical oxygen demand (COD) and 112 mg/l NH4+-N. A mixed culture bacterial biofilm was developed consisting of a heterotrophic bacterium Paracoccus pantotrophus, nitrifiers and other heterotrophs. Applying the peculiar characteristics of P. pantotrophus of simultaneous heterotrophic nitrification and aerobic denitrification, high simultaneous removal of carbon and nitrogen could be achieved in the fully aerobic RBC. The microbial community structure of the RBC biofilm was categorized based on the nitrate reduction, biochemical reactions, gram staining and morphology. The presence of P. pantotrophus within the RBC biofilm was confirmed with an array of biochemical tests. Isolates from the four stages of RBC were grouped into complete denitrifiers, incomplete denitrifiers and non-denitrifiers. This categorization showed a higher relative abundance of P. pantotrophus in the first stage as compared with subsequent stages, in which other nitrifiers and heterotrophs were significantly present. High total nitrogen removal of upto 68% was in conformity with observations made using microbial categorization and biochemical tests. The high relative abundance of P. pantotrophus in the biofilm revealed that it could successfully compete with other heterotrophs and autotrophic nitrifiers in mixed bacterial biomass.

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Zhang, Han, Jiaxin Shi, Cuibai Chen, Meng Yang, Jianping Lu e Baogang Zhang. "Heterotrophic Bioleaching of Vanadium from Low-Grade Stone Coal by Aerobic Microbial Consortium". International Journal of Environmental Research and Public Health 19, n.º 20 (17 de outubro de 2022): 13375. http://dx.doi.org/10.3390/ijerph192013375.

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Bioleaching is a viable method that assists in increasing the vanadium output in an economical and environmentally friendly manner. Most bioleaching is conducted by pure cultures under autotrophic conditions, which frequently require strong acidity and produce acid wastewater. However, little is known about heterotrophic bioleaching of vanadium by mixed culture. This study investigated the bioleaching of vanadium from low-grade stone coal by heterotrophic microbial consortium. According to the results, vanadium was efficiently extracted by the employed culture, with the vanadium recovery percentage in the biosystem being 7.24 times greater than that in the control group without inoculum. The average vanadium leaching concentration reached 680.7 μg/L in the first three cycles. The kinetic equation indicated that the main leaching process of vanadium was modulated by a diffusion process. Scanning electron microscopy revealed traces of bacterial erosion with fluffy structures on the surface of the treated stone coal. X-ray photoelectron spectroscopy confirmed the reduction of the vanadium content in the stone coal after leaching. Analysis of high-throughput 16S rRNA gene sequencing revealed that the metal-oxidizing bacteria, Acidovorax and Delftia, and the heterotrophic-metal-resistant Pseudomonas, were significantly enriched in the bioleaching system. Our findings advance the understanding of bioleaching by aerobic heterotrophic microbial consortium and offer a promising technique for vanadium extraction from low-grade stone coals.

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Xie, Weiying, Xiaojie Li, Huo Xu, Feng Chen, Ka-Wing Cheng, Hongbin Liu e Bin Liu. "Optimization of Heterotrophic Culture Conditions for the Microalgae Euglena gracilis to Produce Proteins". Marine Drugs 21, n.º 10 (29 de setembro de 2023): 519. http://dx.doi.org/10.3390/md21100519.

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Euglena gracilis is one of the few permitted edible microalgae. Considering consumer acceptance, E. gracilis grown heterotrophically with yellow appearances have wider food industrial applications such as producing meat analogs than green cells. However, there is much room to improve the protein content of heterotrophic culture cells. In this study, the effects of nitrogen sources, temperature, initial pH, and C/N ratios on the protein production of E. gracilis were evaluated under heterotrophic cultivation. These results indicated that ammonium sulfate was the optimal nitrogen source for protein production. The protein content of E. gracilis cultured by ammonium sulfate increased by 113% and 44.7% compared with that cultured by yeast extract and monosodium glutamate, respectively. The manipulation of the low C/N ratio further improved E. gracilis protein content to 66.10% (w/w), which was 1.6-fold of that in the C/N = 25 group. Additionally, amino acid analysis revealed that the nitrogen-to-protein conversion factor (NTP) could be affected by nitrogen sources. A superior essential amino acid index (EAAI) of 1.62 and a balanced amino acid profile further confirmed the high nutritional value of E. gracilis protein fed by ammonium sulfate. This study highlighted the vast potency of heterotrophic cultured E. gracilis as an alternative dietary protein source.

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Mozumder, Md Salatul Islam, Laurens Goormachtigh, Linsey Garcia-Gonzalez, Heleen De Wever e Eveline I. P. Volcke. "Modeling pure culture heterotrophic production of polyhydroxybutyrate (PHB)". Bioresource Technology 155 (março de 2014): 272–80. http://dx.doi.org/10.1016/j.biortech.2013.12.103.

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Wang, Ru, Ping Zheng, Ya-Juan Xing, Meng Zhang, Abbas Ghulam, Zhi-qing Zhao, Wei Li e Lan Wang. "Anaerobic ferrous oxidation by heterotrophic denitrifying enriched culture". Journal of Industrial Microbiology & Biotechnology 41, n.º 5 (12 de março de 2014): 803–9. http://dx.doi.org/10.1007/s10295-014-1424-5.

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Obayagbona, O. N., A. Dunkwu-Okafor, O. Odigie e J. U. Oghene. "Biodegradation potentials of edaphic bacterial isolates cultured on Haloxyfop R Methyl ester herbicide-mineral salt medium". Nigerian Journal of Biotechnology 40, n.º 2 (31 de janeiro de 2024): 1–10. http://dx.doi.org/10.4314/njb.v40i2.1.

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The heterotrophic and haloxyfop-R methyl ester utilizing bacterial counts associated with top soil samples was evaluated. Three (3) bacterial isolates; Bacillus sp., Micrococcus sp. and Staphylococcus sp. were cultured and screened for their ability to utilize haloxyfop-R methyl ester as sole source of carbon and energy using the turbidimeteric procedure. The growth profiles of two axenic cultures; Bacillus sp. and Micrococcus sp. were determined using the shake flask test. Parameters which included pH, mean viable bacterial counts, optical density and dissolved CO2 were determined during growth profiling using relevant procedures and equipment. The pH of the soil samples was 5.08 ± 0.02 for sample A and 4.62 ± 0.02 for sample B. The total heterotrophic bacterial count was 2.8 × 104 cfu/g ± 849 for A and 4.62 × 104 cfu/g ± 989 for B. The mean dissolved CO2 data for Micrococcus sp. during the growth profile study ranged from 1.1 mg/l ± 0.1 to 6.8 mg/l ± 0.2. Axenic Micrococcus sp. was the most effective amongst the growth profile cultures in mineralizing the herbicide content of the culture medium.

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Charria-Girón, Esteban, Vanessa Amazo, Daniela De Angulo, Eliana Hidalgo, María Francisca Villegas-Torres, Frank Baganz e Nelson H. Caicedo Ortega. "Strategy for Managing Industrial Anaerobic Sludge through the Heterotrophic Cultivation of Chlorella sorokiniana: Effect of Iron Addition on Biomass and Lipid Production". Bioengineering 8, n.º 6 (10 de junho de 2021): 82. http://dx.doi.org/10.3390/bioengineering8060082.

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Microalgae provides an alternative for the valorization of industrial by-products, in which the nutritional content varies substantially and directly affects microalgae system performance. Herein, the heterotrophic cultivation of Chlorella sorokiniana was systematically studied, allowing us to detect a nutritional deficiency other than the carbon source through assessing the oxygen transfer rate for glucose or acetate fermentation. Consequently, a mathematical model of the iron co-limiting effect on heterotrophic microalgae was developed by exploring its ability to regulate the specific growth rate and yield. For instance, higher values of the specific growth rate (0.17 h−1) compared with those reported for the heterotrophic culture of Chlorella were obtained due to iron supplementation. Therefore, anaerobic sludge from an industrial wastewater treatment plant (a baker’s yeast company) was pretreated to obtain an extract as a media supplement for C. sorokiniana. According to the proposed model, the sludge extract allowed us to supplement iron values close to the growth activation concentration (KFe ~12 mg L−1). Therefore, a fed-batch strategy was evaluated on nitrogen-deprived cultures supplemented with the sludge extract to promote biomass formation and fatty acid synthesis. Our findings reveal that nitrogen and iron in sludge extract can supplement heterotrophic cultures of Chlorella and provide an alternative for the valorization of industrial anaerobic sludge.

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Hršak, Dubravka, e Ana Begonja. "Possible Interactions within a Methanotrophic-Heterotrophic Groundwater Community Able To Transform Linear Alkylbenzenesulfonates". Applied and Environmental Microbiology 66, n.º 10 (1 de outubro de 2000): 4433–39. http://dx.doi.org/10.1128/aem.66.10.4433-4439.2000.

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ABSTRACT The relationships and interactions within a methanotrophic-heterotrophic groundwater community were studied in a closed system (shake culture) in the presence of methane as the primary carbon and energy source and with the addition of the pure linear alkylbenzenesulfonate (LAS) congener 2-[4-(sulfophenyl)]decan as a cometabolic substrate. When cultured under different conditions, this community was shown to be a stable association, consisting of one obligate type II methanotroph and four or five heterotrophs possessing different nutritional and physiological characteristics. The results of experiments examining growth kinetics and nutritional relationships suggested that a number of complex interactions existed in the community in which the methanotroph was the only member able to grow on methane and to cometabolically initiate LAS transformation. These growth and metabolic activities of the methanotroph ensured the supply of a carbon source and specific nutrients which sustained the growth of four or five heterotrophs. In addition to the obligatory nutritional relationships between the methanotroph and heterotrophs, other possible interactions resulted in the modification of basic growth parameters of individual populations and a concerted metabolic attack on the complex LAS molecule. Most of these relationships conferred beneficial effects on the interacting populations, making the community adaptable to various environmental conditions and more efficient in LAS transformation than any of the individual populations alone.

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Gao, Yu Qiang, Qiu Yan Zhang, Li Huang, Lin Wang e Xu Ya Yu. "The Influence of Various pH Values on Monoraphidium sp. FXY-10 Growth and Lipid Parameters in Autotrophic and Heterotrophic Conditions". Advanced Materials Research 864-867 (dezembro de 2013): 60–66. http://dx.doi.org/10.4028/www.scientific.net/amr.864-867.60.

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The influence of pH on Monoraphidium sp. FXY-10 growth, lipid content, lipid yield, biomass yield, and fatty acid composition is studied in autotrophic and heterotrophic conditions. The results reveal that Monoraphidium sp. FXY-10 can grow better in an acidic environment. Under autotrophic and heterotrophic conditions, the culture time is 37 and 9 day, respectively. And the maximum biomass of algal cells is 32 and 367mg/l/d with the lipid content in autotrophic and heterotrophic conditions reached to 49% and 39%, respectively, with high biomass yield, lipid yield, the saturated fatty acid and monounsaturated fatty acid under heterotrophic condition, proving that the algal cells are a viable material for the production of biodiesel.

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Velioğlu Tosuner, Zülfiye, e Raziye Öztürk Ürek. "Cultivation of Arthrospira platensis in heterotrophic and mixotrophic conditions with different concentrations of whey". Aquatic Research 5, n.º 2 (2022): 146–53. http://dx.doi.org/10.3153/ar22014.

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Wastes left over from human food production is commonly used to produce feed for animals, which is an important issue for a rational utilization of food sources globally, and a topic that attracts researcher for the establishment of best food production management. Whey as a side product from cheese production has great potentials in terms of nutritional value for both human food and animal feed production. This study aimed to investigate the possible use of whey (1, 10 and 30%, v/v) as an external carbon source for mixotrophic and heterotrophic cultivation of the cyanobacterium Arthrospira platensis. The highest specific growth rate (µ = 0.2 day-1), protein (3.76 ±0.14 mg/ g cell) and lipid (4.67 ±0.18 mg/g cell) contents were detected in heterotrophic culture while the highest chlorophyll-a (292.39 ±1.31 mg/ g cell) and total carbohydrate (1.42 ±0.07 mg/ g cell) contents were found in mixotrophic culture. In heterotrophic cultivation, it can be noted that the absorbed organic carbon source increased cell counts and triggered especially lipid production. In the mixotrophic cultivation, carbon absorbed from the culture medium or CO2 captured with chlorophyll was utilized in the production of total carbohydrate. This study provides evidence that a cyanobacterium can adapt to heterotrophic conditions without light, creating an example for an economic and ecological production model for biochemical components.

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Chen, Feng. "High cell density culture of microalgae in heterotrophic growth". Trends in Biotechnology 14, n.º 11 (novembro de 1996): 421–26. http://dx.doi.org/10.1016/0167-7799(96)10060-3.

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Parrow, Matthew W., e JoAnn M. Burkholder. "ESTUARINE HETEROTROPHIC CRYPTOPERIDINIOPSOIDS (DINOPHYCEAE): LIFE CYCLE AND CULTURE STUDIES1". Journal of Phycology 39, n.º 4 (28 de julho de 2003): 678–96. http://dx.doi.org/10.1046/j.1529-8817.2003.02146.x.

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Jia, Shi Ru, Zhen Ding, Ning Tan, Nan Wang, Pei Pei Han e Nan Nan Yuan. "Heterotrophic Fed-Batch Cultures of Nostoc flagelliforme and Production of Extracellular Polysaccharides". Advanced Materials Research 518-523 (maio de 2012): 5468–71. http://dx.doi.org/10.4028/www.scientific.net/amr.518-523.5468.

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Nostoc flagelliforme is a kind of terrestrial cyanobacterium with high economic value. Dissociated cells, which separated from a natural colony of N. flagelliforme, could be cultivated heterotrophically in the darkness on xylose and glucose under fed-batch culture conditions. Growth and extracellular polysaccharides (EPS) production in different cultures are investigated. At harvest time, the cultures contain 1.215 g•L-1 of biomass and 122.5 mg•L-1 of EPS respectively. The gravimetric EPS production rate is 17.5 mg•g-1•day-1, which is 1.65 times higher than previously reported results for heterotrophic Nostoc flagelliforme grown on xylose batch culture.

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Fruhen, M., E. Christan, W. Gujer e O. Wanner. "Significance of Spatial Distribution of Microbial Species in Mixed Culture Biofilms". Water Science and Technology 23, n.º 7-9 (1 de abril de 1991): 1365–74. http://dx.doi.org/10.2166/wst.1991.0589.

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Experimental data from a biofilm reactor, in which two groups of organisms (Nitrifiers and Heterotrophs) compete for dissolved oxygen, were analyzed by a Mixed Culture Biofilm Model. The objective was to investigate to what extent and how fast relative abundance and spatial distribution of microbial species in a mixed culture biofilm changed upon variations of the bulk fluid substrate composition, and what the consequences of these changes were for substrate removal. Experimental results showed that within nine days the nitrification rate in a biofilm of constant thickness could change by a factor of five. Model predictions indicated that these changes must be due to a significant shift of the biofilm population. The distribution of the autotrophic and heterotrophic species over the depth of the biofilm turned out to be an important aspect of mixed culture biofilm behavior. Since it is difficult to observe the microbial population and its spatial distribution experimentally, the Mixed Culture Biofilm Model has proved to be a valuable tool for the interpretation of the observed phenomena.

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Yamamoto-Ikemoto, R., T. Komori, M. Nomuri, Y. Ide e T. Matsukami. "Nitrogen removal from hydroponic culture wastewater by autotrophic denitrification using thiosulfate". Water Science and Technology 42, n.º 3-4 (1 de agosto de 2000): 369–76. http://dx.doi.org/10.2166/wst.2000.0405.

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Using the upflow biological filter reactor, sulfur denitrification using thiosulfate of hydroponic culture wastewater was examined. Start-up periods of the reactor were one to two weeks. About 90% of nitrogen removal ratio were achieved over 80 days, at 6.3 kg/m3·days of nitrogen loading. Shock loading among 0.56-2.8 kgN/m3· day did not affect the reactor performance. However, when temperature went below 15°C, the effluent characteristics became poor. Suitable S/N and IC/N ratios were calculated as 3.3 and 0.15, respectively. The activities of sulfur denitrification, heterotrophic denitrification and sulfur reduction were examined by the bath experiments under several conditions using biomass grown in the reactor. In the anoxic conditions, denitrification using thiosulfate was occurred stoichiometrically in the presence of thiosulfate. The denitrification activity was highest (17 mgN/gBiomass·hr). When the electron donor was not added to the substrate, denitrification occurred using sulfur granules accumulated in the biomass. Seventy mg of sulfur granule were accumulated in one g of biomass. The denitrification activity using sulfur granules was 2.9-5.0 mgN/gBiomass·hr. Heterotrophic denitrification occurred in the presence of organic matter. The activities were 1.4-5.4 mgN/gBiomass·hr. In the anaerobic conditions, the accumulated sulfur was reduced to sulfide at a rate of 1.4 mgS/gBiomass·hr. These results suggested that sulfur denitrification, heterotrophic denitrification and sulfur reduction bacteria coexisted in the biofilm and sulfur cycle was established in the reactor. Accumulated sulfur plays an important role in the sulfur denitrification.

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Tisserat, Brent, e Robert Silman. "Growth of Plant Tissue Cultures in Ultra-high Levels of Carbon Dioxide under Autotrophic and Heterotrophic Conditions". HortScience 31, n.º 4 (agosto de 1996): 587e—587. http://dx.doi.org/10.21273/hortsci.31.4.587e.

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A comparative study was undertaken to determine the influence of lighting, carbohydrate concentrations and ultra-high levels of CO2, i.e., >10,000 ppm, on sterile culture growth. Past CO2-sterile studies have confirmed that elevation of CO2 to as high as 1000 ppm resulted in beneficial growth. Within special constructed chambers, tissue cultures were given a variety of CO2 levels for 12–16 hours/day using artificial lighting and natural sunlight. Several different plants (lettuce, beans, pine) and plant culture types were grown in CO2-enriched environments, ranging from 350 to 50,000 ppm. In almost all cases, plant tissue cultures not only tolerated but exhibited enhanced growth using ultra-high levels of CO2. For example, lettuce cultures were found to grow 2 to 4 times faster under ultra-high CO2. levels than under normal atmospheric CO2 levels, i.e., 350 ppm. Natural sunlight was found to be suitable for sterile culture growth. Modes of administration of CO2 in vitro and gas permeability of various culture vessels are presented.

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Orphan, V. J., L. T. Taylor, D. Hafenbradl e E. F. Delong. "Culture-Dependent and Culture-Independent Characterization of Microbial Assemblages Associated with High-Temperature Petroleum Reservoirs". Applied and Environmental Microbiology 66, n.º 2 (1 de fevereiro de 2000): 700–711. http://dx.doi.org/10.1128/aem.66.2.700-711.2000.

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ABSTRACT Recent investigations of oil reservoirs in a variety of locales have indicated that these habitats may harbor active thermophilic prokaryotic assemblages. In this study, we used both molecular and culture-based methods to characterize prokaryotic consortia associated with high-temperature, sulfur-rich oil reservoirs in California. Enrichment cultures designed for anaerobic thermophiles, both autotrophic and heterotrophic, were successful at temperatures ranging from 60 to 90°C. Heterotrophic enrichments from all sites yielded sheathed rods (Thermotogales), pleomorphic rods resemblingThermoanaerobacter, and Thermococcus-like isolates. The predominant autotrophic microorganisms recovered from inorganic enrichments using H2, acetate, and CO2 as energy and carbon sources were methanogens, including isolates closely related to Methanobacterium,Methanococcus, and Methanoculleus species. Two 16S rRNA gene (rDNA) libraries were generated from total community DNA collected from production wellheads, using either archaeal or universal oligonucleotide primer sets. Sequence analysis of the universal library indicated that a large percentage of clones were highly similar to known bacterial and archaeal isolates recovered from similar habitats. Represented genera in rDNA clone libraries includedThermoanaerobacter, Thermococcus,Desulfothiovibrio, Aminobacterium,Acidaminococcus, Pseudomonas,Halomonas, Acinetobacter,Sphingomonas, Methylobacterium, andDesulfomicrobium. The archaeal library was dominated by methanogen-like rDNAs, with a lower percentage of clones belonging to the Thermococcales. Our results strongly support the hypothesis that sulfur-utilizing and methane-producing thermophilic microorganisms have a widespread distribution in oil reservoirs and the potential to actively participate in the biogeochemical transformation of carbon, hydrogen, and sulfur in situ.

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Gurung, Anirudra, e Ranadhir Chakraborty. "The role ofAcidithiobacillus ferrooxidansin alleviating the inhibitory effect of thiosulfate on the growth of acidophilicAcidiphiliumspecies isolated from acid mine drainage samples from Garubathan, India". Canadian Journal of Microbiology 55, n.º 9 (setembro de 2009): 1040–48. http://dx.doi.org/10.1139/w09-062.

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Several acidophilic chemolithoautotrophic and heterotrophic strains were isolated from acid mine drainage samples from Garubathan, West Bengal, India. The strains, chemolithoautotrophic DK6.1 and heterotrophic DKAP1.1, used in this study were assigned to the species Acidithiobacillus ferrooxidans and Acidiphilium cryptum , respectively. Unamended filtered and subsequently autoclaved elemental sulfur spent medium of A. ferrooxidans was used as the medium to study heterotrophic growth of A. cryptum DKAP1.1. While characterizing the heterotrophic strain, an inhibitory effect of thiosulfate on A. cryptum DKAP1.1 was identified. The lethality of thiosulfate broth was directly related to the concentration of thiosulfate in the medium. Nonviability of A. cryptum DKAP1.1 in the presence of thiosulfate was alleviated by A. ferrooxidans DK6.1 in co-culture. Microbiological data on a positive growth effect for A. ferrooxidans DK6.1 caused by co-culturing in solid media in the presence of A. cryptum DKAP1.1 is also presented.

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Dong, Kaiyi, Ying Wang, Wenjing Zhang e Qian Li. "Prevalence and Preferred Niche of Small Eukaryotes with Mixotrophic Potentials in the Global Ocean". Microorganisms 12, n.º 4 (8 de abril de 2024): 750. http://dx.doi.org/10.3390/microorganisms12040750.

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Unicellular eukaryotes that are capable of phago-mixotrophy in the ocean compete for inorganic nutrients and light with autotrophs, and for bacterial prey with heterotrophs. In this study, we ask what the overall prevalence of eukaryotic mixotrophs in the vast open ocean is, and how the availability of inorganic nutrients, light, and prey affects their relative success. We utilized the Tara Oceans eukaryotic 18S rRNA gene and environmental context variables dataset to conduct a large-scale field analysis. We also performed isolate-based culture experiments to verify growth and nutritional resource relationships for representative mixotrophic taxa. The field analysis suggested that the overall prevalence of mixotrophs were negatively correlated with nutrient concentrations and positively associated with light availability. Concentrations of heterotrophic bacteria as a single variable also presented a positive correlation with mixotrophic prevalence, but to a lesser extent. On the other hand, the culture experiments demonstrated a taxa-specific relationship between mixotrophic growth and nutrition resources, i.e., the growth of one group was significantly dependent on light availability, while the other group was less affected by light when they received sufficient prey. Both groups were capable of growing efficiently with low inorganic nutrients when receiving sufficient prey and light. Therefore, our field analysis and culture experiments both suggest that phago-mixotrophy for ocean eukaryotes is seemingly an efficient strategy to compensate for nutrient deficiency but unnecessary to compensate for light scarcity. This study collectively revealed a close relationship between abiotic and biotic nutritional resources and the prevalence of trophic strategies, shedding light on the importance of light and nutrients for determining the competitive success of mixotrophs versus autotrophic and heterotrophic eukaryotes in the ocean.

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Mével, Geneviève, e Daniel Prieur. "Heterotrophic nitrification by a thermophilicBacillusspecies as influenced by different culture conditions". Canadian Journal of Microbiology 46, n.º 5 (1 de maio de 2000): 465–73. http://dx.doi.org/10.1139/w00-005.

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The nitrification activity of a thermophilic heterotrophic bacterium, Bacillus MS30 isolated from a deep-sea hydrothermal vent, was studied under various growth conditions. Nitrification was estimated from the nitrogen balance calculations in the culture media. The results showed that this isolate actively nitrified in culture conditions similar to those prevailing in hydrothermal sites. Therefore, its ecological significance was considered. In standard aerobic conditions, MS30 produced nitrite from ammonia and acetate (1.13 µmol NO2-·mg-1dry wt), but nitrate was never produced, and a low nitrite reduction was often observed. Higher nitrification activities were observed in defined optimal conditions (simple carbon substrate, 65°C, pH 7.5, and 15 g sea salts · L-1). In addition, discrepancies between the optima for growth and nitrification were observed, showing the ability of MS30 to adapt to changing environmental conditions typical of hydrothermal sites.Key words: thermophilic bacteria, heterotrophic nitrification, environmental parameters.

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Chen, Feng, e Michael R. Johns. "Heterotrophic growth of Chlamydomonas reinhardtii on acetate in chemostat culture". Process Biochemistry 31, n.º 6 (agosto de 1996): 601–4. http://dx.doi.org/10.1016/s0032-9592(96)00006-4.

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Tsavalos, Alexander J., e John G. Day. "Development of media for the mixotrophic/heterotrophic culture ofBrachiomonas submarina". Journal of Applied Phycology 6, n.º 4 (agosto de 1994): 431–33. http://dx.doi.org/10.1007/bf02182162.

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Day, John G., e Alexander J. Tsavalos. "An investigation of the heterotrophic culture of the green algaTetraselmis". Journal of Applied Phycology 8, n.º 1 (janeiro de 1996): 73–77. http://dx.doi.org/10.1007/bf02186225.

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Ohira, Yuichi, Wataru Fukuchi, Masamitsu Shimadzu e Eiji Obata. "Effect of Organic Substrates on Heterotrophic Culture of Spirulina platensis". KAGAKU KOGAKU RONBUNSHU 35, n.º 5 (2009): 553–56. http://dx.doi.org/10.1252/kakoronbunshu.35.553.

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Chen, Feng, e Michael R. Johns. "Substrate inhibition of Chlamydomonas reinhardtii by acetate in heterotrophic culture". Process Biochemistry 29, n.º 4 (janeiro de 1994): 245–52. http://dx.doi.org/10.1016/0032-9592(94)80064-2.

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Okabe, Satoshi, Tomonori Kindaichi e Tsukasa Ito. "Fate of 14C-Labeled Microbial Products Derived from Nitrifying Bacteria in Autotrophic Nitrifying Biofilms". Applied and Environmental Microbiology 71, n.º 7 (julho de 2005): 3987–94. http://dx.doi.org/10.1128/aem.71.7.3987-3994.2005.

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ABSTRACT The cross-feeding of microbial products derived from 14C-labeled nitrifying bacteria to heterotrophic bacteria coexisting in an autotrophic nitrifying biofilm was quantitatively analyzed by using microautoradiography combined with fluorescence in situ hybridization (MAR-FISH). After only nitrifying bacteria were labeled with [14C]bicarbonate, biofilm samples were incubated with and without NH4 + as a sole energy source for 10 days. The transfer of 14C originally incorporated into nitrifying bacterial cells to heterotrophic bacteria was monitored with time by using MAR-FISH. The MAR-FISH analysis revealed that most phylogenetic groups of heterotrophic bacteria except the β-Proteobacteria showed significant uptake of 14C-labeled microbial products. In particular, the members of the Chloroflexi were strongly MAR positive in the culture without NH4 + addition, in which nitrifying bacteria tended to decay. This indicated that the members of the Chloroflexi preferentially utilized microbial products derived from mainly biomass decay. On the other hand, the members of the Cytophaga-Flavobacterium cluster gradually utilized 14C-labeled products in the culture with NH4 + addition in which nitrifying bacteria grew. This result suggested that these bacteria preferentially utilized substrate utilization-associated products of nitrifying bacteria and/or secondary metabolites of 14C-labeled structural cell components. Our results clearly demonstrated that the coexisting heterotrophic bacteria efficiently degraded and utilized dead biomass and metabolites of nitrifying bacteria, which consequently prevented accumulation of organic waste products in the biofilm.

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Wang, Yuxin, Jia Wang, Shufang Yang, Qingping Liang, Ziqiang Gu, Ying Wang, Haijin Mou e Han Sun. "Selecting a preculture strategy for improving biomass and astaxanthin productivity of Chromochloris zofingiensis". Applied Microbiology and Biotechnology 108, n.º 1 (10 de janeiro de 2024): 1–17. http://dx.doi.org/10.1007/s00253-023-12873-x.

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Abstract Chromochloris zofingiensis is a potential source of natural astaxanthin; however, its rapid growth and astaxanthin enrichment cannot be achieved simultaneously. This study established autotrophic, mixotrophic, and heterotrophic preculture patterns to assess their ameliorative effect on the C. zofingiensis heterotrophic growth state. In comparison, mixotrophic preculture (MP) exhibited the best improving effect on heterotrophic biomass concentration of C. zofingiensis (up to 121.5 g L−1) in a 20 L fermenter, reaching the global leading level. The astaxanthin productivity achieved 111 mg L−1 day−1, 7.4-fold higher than the best record. The transcriptome and 13C tracer-based metabolic flux analysis were used for mechanism inquiry. The results revealed that MP promoted carotenoid and lipid synthesis, and supported synthesis preference of low unsaturated fatty acids represented by C18:1 and C16:0. The MP group maintained the best astaxanthin productivity via mastering the balance between increasing glucose metabolism and inhibition of carotenoid synthesis. The MP strategy optimized the physiological state of C. zofingiensis and realized its heterotrophic high-density growth for an excellent astaxanthin yield on a pilot scale. This strategy exhibits great application potential in the microalgae-related industry. Key points • Preculture strategies changed carbon flux and gene expression in C. zofingiensis • C. zofingiensis realized a high-density culture with MP and fed-batch culture (FBC) • Astaxanthin productivity achieved 0.111 g L−1day−1with MP and FBC Graphical Abstract

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Eze, C. N., I. O. Ogbonna e J. C. Ogbonna. "Growth, lipids, proteins, and carotenoid contents of some freshwater green microalgae under simulated day/night temperature fluctuation". Nigerian Journal of Biotechnology 39, n.º 1 (3 de agosto de 2022): 9–19. http://dx.doi.org/10.4314/njb.v39i1.2.

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Day/night or seasonal temperature fluctuation is a major factor during outdoor cultivation of microalgae. In the present study, we investigated the impact of simulated day/night temperatures (20oC night and 30oC day) on the growth, lipid, protein and carotenoid contents of four local oleaginous microalgae strains under mixotrophic and heterotrophic conditions. The impact of simulated day/night temperatures on the growth and biochemical compositions varied across species and culture conditions (mixotrophic or heterotrophic). The lipid productivity by Dictyosphaerium sp. under heterotrophic condition was twice the value obtained at constant temperature but showed no significant (p > 0.05) impact under mixotrophic condition. Desmodesmus subspicatus elicited higher lipid (15%) and carotenoid (56%) contents under simulated day/night temperature regime than at constant temperature (30oC) (p<0.05). There was a negative impact on the protein content of the microalgal species under mixotrophic and heterotrophic conditions. The above results have shown that these species have high potentials for co-production of lipids, protein and carotenoid under outdoor conditions.

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Parra-Riofrío, Geovanna, Jorge García-Márquez, Virginia Casas-Arrojo, Eduardo Uribe-Tapia e Roberto Teófilo Abdala-Díaz. "Antioxidant and Cytotoxic Effects on Tumor Cells of Exopolysaccharides from Tetraselmis suecica (Kylin) Butcher Grown Under Autotrophic and Heterotrophic Conditions". Marine Drugs 18, n.º 11 (26 de outubro de 2020): 534. http://dx.doi.org/10.3390/md18110534.

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Marine microalgae produce extracellular metabolites such as exopolysaccharides (EPS) with potentially beneficial biological applications to human health, especially antioxidant and antitumor properties, which can be increased with changes in crop trophic conditions. This study aimed to develop the autotrophic and heterotrophic culture of Tetraselmis suecica (Kylin) Butcher in order to increase EPS production and to characterize its antioxidant activity and cytotoxic effects on tumor cells. The adaptation of autotrophic to heterotrophic culture was carried out by progressively reducing the photoperiod and adding glucose. EPS extraction and purification were performed. EPS were characterized by Fourier-transform infrared spectroscopy and gas chromatography-mass spectrometry. The antioxidant capacity of EPS was analyzed by the 2,2’-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) method, and the antitumor capacity was measured by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, showing high activity on human leukemia, breast and lung cancer cell lines. Although total EPS showed no cytotoxicity, acidic EPS showed cytotoxicity over the gingival fibroblasts cell line. Heterotrophic culture has advantages over autotrophic, such as increasing EPS yield, higher antioxidant capacity of the EPS and, to the best of our knowledge, this is the first probe that T. suecica EPS have cytotoxic effects on tumor cells; therefore, they could offer greater advantages as possible natural nutraceuticals for the pharmaceutical industry.

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Berger, R. G., Z. Akkan e F. Drawert. "The Essential Oil of Coleonema album (Rutaceae) and of a Photomixotrophic Cell Culture Derived thereof". Zeitschrift für Naturforschung C 45, n.º 3-4 (1 de abril de 1990): 187–95. http://dx.doi.org/10.1515/znc-1990-3-408.

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Abstract The volatile shoot oil of Coleonema album was found to be composed of monoterpenes, sesquiterpenes and phenylpropanoids. Heterotrophic and photom ixotrophic callus cultures were established from green parts of the plant. A photom ixotrophic cell line contained a heterogeneous population of plastids and synthesized an essential oil, which differed qualitatively and quantitatively from the green parts of the intact plant. Substitution of 2,4-D and pCPA by a lower amount of NAA and high kinetin concentrations favoured the formation of essential oil. The heterotrophic callus, when grown on the same nutrient medium, was devoid of any differ entiated plastids and of essential oil constituents. Thus, a close correlation of light-induced plastid differentiation and essential oil synthesis was concluded.

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Inamori, Yuhei, Xiao-Lei Wu e Motoyuki Mizuochi. "N2O producing capability of nitrosomonas europaea, nitrobacter winogradskyi and alcaligenes faecalis". Water Science and Technology 36, n.º 10 (1 de novembro de 1997): 65–72. http://dx.doi.org/10.2166/wst.1997.0360.

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Nitrosomonas europaea, Nitrobacter winogradskyi and Alcaligenes faecalis—typical ammonia-oxidizer, nitrite-oxidizer and heterotrophic nitrifier were immobilized in PVA gel and employed in the study. Continuous experiments were conducted in their pure and mixed cultures with DO concentrations in the cultures kept at 4, 2, 0.5 mg·l−1. Comparisons among N2O emission from different cultures were made to show their N2O producing capabilities. Results showed that: compared with N. europaea and A. faecalis, N. winogradskyi produced negligible N2O. On the other hand, N. europaea had the highest N2O producing ability. Unit N. europaea produced N2O 18–53 times higher than unit A. faecalis did. However, due to the higher population of A. faecalis, N2O production of the A. faecalis culture was higher than that of the N. europaea culture when DO concentration in the cultures was 2 mg·l−1; whereas, N2O yields of the A. faecalis culture were smaller than those of the N. europaea culture at DO concentrations of 4 and 0.5 mg·l−1. N2O emitted from most the mixed cultures was lower than that from pure cultures under the experimental conditions.

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