Littérature scientifique sur le sujet « Pigmenti fotosintetici »

ABSTRAKCahaya matahari merupakan salah satu faktor lingkungan terpenting baik secara langsung maupun tidak langsung bagi organisme fotosintetik perairan dalam menyediakan energi untuk diubah menjadi energi kimia dengan bantuan klorofil. Penelitian ini bertujuan untuk mengkaji hubungan antara ketersediaan cahaya matahari dan konsentrasi pigmen fotosintetik di Perairan Selat Bali. Penelitian dilaksanakan pada pagi, siang dan sore hari pada lima stasiun penelitian di Perairan Selat Bali. Analisis korelasi kanonik digunakan untuk mengetahui hubungan antara ketersediaan cahaya matahari dan pembentukan pigmen fotosintetik. Hasil penelitian menunjukkan bahwa intensitas cahaya matahari (Y2) lebih berpengaruh terhadap pembentukan pigmen klorofil-b (Y1) dengan korelasi kanonik sebesar 0,4512 bilamana dibandingkan dengan pembentukan pigmen klorofil-a (Y1) dengan nilai korelasi sebesar 0,3982. Semakin tinggi pembentukan pigmen klorofil-b (Y1) dapat meningkatkan pembentukan pigmen karotenoid (Y1) secara signifikan dengan nilai korelasi kanonik sebesar 0,7419. Kesimpulan dari hasil ini, bahwa pigmen klorofil-b dan pigmen karotenoid akan terbentuk secara optimum pada intensitas cahaya rendah. ABSTRACTSunlight is one of the most important environmental factors both directly and indirectly for photosynthetic organisms in providing energy to be converted into chemical energy with the help of chlorophyll. This study aims to examine the relationship between the availability of sunlight and the concentration of photosynthetic pigments in Bali Strait waters. The study was conducted in the morning, midday and afternoon at five research stations in the Bali Strait waters. Canonical correlation analysis was used to determine the relationship between sunlight availability and photosynthetic pigment formation. The results showed that the intensity of sunlight (Y2) had more influence on the formation of chlorophyll-b (Y1) pigments with canonical correlation of 0.4512 when compared with the formation of chlorophyll-a (Y1) pigment with a correlation value of 0.3982. The higher formation of chlorophyll-b (Y1) pigments can significantly increase the formation of carotenoid pigments (Y1) with canonical correlation values of 0.7419. From these results it can be concluded that chlorophyll-b pigments and carotenoid pigments will be formed optimally at low light intensities.

Dunaliella salina merupakanfitoplankton Chlorophytayang potensial dikembangkan sebagai pakan alami, memiliki kandungan pigmen fotosintetikuntuk merespon intensitas cahaya dalam proses fotosintesisyakni klorofil dan karotenoid. Salah satu pemanfaatan pigmen fotosintetiksebagai sumber antioksidan. Sejauhini Pembudidaya ikan menggunakanpakan buatan maupun antioksidan sintestis dalam jumlah tinggi. Kajian ini diharapkan mampu meminimalisir penggunaan antioksidan sintetis dengan pemanfaatan pigmen fotosintetik. D. salina memiliki kemampuanmengakumulasi sejumlah pigmen fotosintetik dalam jumlah tinggi padakondisi terstimulasi, salah satunya adanya intensitas cahaya tinggi.Penelitian ini bertujuan untuk mengetahui intensitas cahaya yang dapat diresponpigmen fotosintetik secara optimal. Kajian menggunakanmetode eksperimental dengan variasiintensitas cahaya 500 lux(A);1029 lux(B); 2000 lux(C). D. salina dikulturpada media walne 1L (3x ulangan)tiap perlakuan. Konsentrasi pigmen fotosintetik klorofil a, b dan karotenoid (mg/m3)diukur menggunakan spektrofotometer UV-Vis pada absorbansi 470, 652 dan 665 nm. Hasil menunjukkan optimalitas konsentrasi klorofil a (0,049±0,015)mg/m3, klorofil b (0,055±0,025) mg/m3 dan karotenoid (0,178±0,122) mg/m3 pada intensitas cahaya tinggi (2000 lux). Hal ini membuktikanintensitas cahaya tinggi menyebabkan kondisi terstimulasi, yangmenyebabkanD.Salinamengakumulasi sejumlah pigmen fotosintetik dalam jumlah tinggi. D.salinamampu berstrategi mentoleransi intensitas cahaya tinggi hingga ambang batas tertentuuntuk mencapai optimalisasi pigmen, pembentukan produk fotosintesisserta menghasilkansenyawa antioksidan. Dunaliella salina is a Chlorophyta phytoplankton that has the potential to be developed as natural food, containing photosynthetic pigments to respond to light intensity in the photosynthesis process that is chlorophyll and carotenoids. One of the utilization of photosynthetic pigments as a source of antioxidants. So far, many fish cultivators use artificial feed and synthetic antioxidants. This research is expected to minimize the use of synthetic antioxidants by using photosynthetic pigments. D. salina has the ability to accumulate high amounts of photosynthetic pigments under stimulated conditions, one of which is the presence of high light intensity. This study aims to determine the optimal light intensity that can be responded by photosynthetic pigments. The study used an experimental method with variations in light intensity of 500 lux(A); 1029lux(B); 2000 lux(C). D. salina was cultured on 1L Walne medium (3x replicates) for each treatment. The concentrations of photosynthetic pigments chlorophyll a, b and carotenoids (mg/m3) were measured using a UV-Vis spectrophotometer at absorbances of 470, 652 and 665 nm. The results showed that the optimal concentration of chlorophyll a (0.049±0.015) mg/m3, chlorophyll b (0.055±0.025) mg/m3 and carotenoids (0.178±0.122) mg/m3 at high light intensity (2000 lux). This proves that high light intensity causes a stimulated condition, which causes D. Salina to accumulate high amounts of photosynthetic pigments. D.salina is able to tolerate strategies of high light intensity up to a certain threshold to achieve pigment optimization, formation of photosynthetic products and produce antioxidant compounds.

Carotenoids are pigments with a range of red, orange and yellow colors. In carotenoid and chlorophyll plants are located in chloroplasts which undergo photosynthesis as well as photosynthetic bacteria and fungi. Carotenoid compounds have antioxidant activity, anticancer, as precursors of vitamin A and can enhance immunity. Crustaceans like crabs Grapsus sp. have carotenoid pigments, visible red, orange, and yellow are scattered in the carapace. Pigments found in crustaceans as well as crabs of Grapsus sp. generally sourced from food eaten by the crab. To determine the process of carotenoid pigment metabolism, each crab organ of Grapsus sp. isolated using thin layer chromatography separation method and column chromatography to determine the type of pigment contained therein. Pigment types identified in the crabs of Grapsus sp. males using the TLC method: β-carotene, Astasen type, Cantasantin, Astasantin, and Adonirubin. Pigment types identified in the crabs of Grapsus sp. males using the CC method: β-carotene, Astasen, β-cryptosanthine, Zeaxantine, and Cryptosanthine. Keywords : Grapsus sp., Thin Layer Chromatography, Column Chromatography, Carotenoids Pigments. Karotenoid merupakan pigmen dengan kisaran warna merah, orange dan kuning. Pada tumbuhan karotenoid dan klorofil terletak pada kloroplas yang mengalami proses fotosintesis seperti juga pada bakteri fotosintetik dan fungi. Senyawa karotenoid memiliki aktivitas antioksidan, antikanker, sebagai prekursor vitamin A dan dapat meningkatkan imunitas. Krustasea seperti kepiting Grapsus sp. mempunyai pigmen karotenoid, terlihat warna merah, jingga, dan kuning yang tersebar pada karapas. Pigmen yang terdapat pada krustasea demikian juga pada kepiting Grapsus sp. umumnya bersumber dari makanan yang dimakan oleh kepiting tersebut. Untuk mengetahui proses metabolisme pigmen karotenoid maka masing-masing organ kepiting Grapsus sp. diisolasi dengan menggunakan metode pemisahan kromatografi lapis tipis dan kromatografi kolom untuk mengetahui jenis pigmen yang terkandung didalamnya. Jenis pigmen yang teridentifikasi pada kepiting Grapsus sp. jantan dengan metode KLT yaitu : β- karoten, Tipe Astasen, Kantasantin, Astasantin, dan Adonirubin. Jenis pigmen yang teridentifikasi pada kepiting Grapsus sp. jantan dengan metode KK yaitu : β- karoten, Astasen, β-kriptosantin, Zeaxantin, dan Kriptosantin. Kata Kunci : Grapsus sp., Kromatografi Lapis Tipis, Kromatografi Kolom, Pigmen Karotenoid.

Avicennia marina merupakan mangrove mayor yang mampu bertahan hidup di kondisi ekstrim seperti intensitas cahaya, suhu dan kadar garam tinggi. Kondisi ekstrim berpengaruh terhadap sintesis dan reduksi pigmen fotosintetik. Cekaman intensitas cahaya dan salinitas memicu A. marina membentuk fenol sebagai senyawa pertahanan pada kondisi kurang menguntungkan. A. marina pada kawasan Mangunharjo tumbuh baik pada lingkungan pantai dan tambak. Tujuan penelitian ini untuk mengetahui pengaruh lingkungan pantai dan tambak terhadap kandungan pigmen fotosintetik dan total fenol daun A. marina. Penelitian dilakukan dengan metode observasi dengan melibatkan lokasi pantai dan tambak. Penelitian menggunakan Rancangan Acak Lengkap (RAL) satu faktor organ daun A. marina yang hidup di lingkungan pantai dan tambak. Daerah pengamatan dibagi menjadi 6 titik pengambilan sampel. Parameter penelitian yang diamati adalah intensitas cahaya, suhu, salinitas, pigmen fotosintetik (klorofil a, klorofil b, karotenoid) dan total fenol daun A. marina. Analisis data menggunakan Uji T dengan taraf kepercayaan 95%. Hasil penelitian menunjukkan bahwa daun A. marina di pantai memiliki kandungan pigmen fotosintetik dan total fenol lebih rendah dibanding tambak. Hal ini menunjukkan bahwa lingkungan pantai dan tambak berpengaruh nyata terhadap kandungan pigmen fotosintetik dan fenol. Intensitas cahaya dan salinitas tinggi di pantai mengganggu pembentukan klorofil dan Phenylalanine Ammonia Lyase(PAL). Avicennia marina is a major mangrove that is able to survive in extreme conditions such as light intensity, temperature and high salt content. Extreme conditions affect the synthesis and reduction of photosynthetic pigments. The stress of light intensity and salinity triggered A. marina to form phenol as a defense compound under unfavorable conditions. A. marina in the Mangunharjo area grows well in coastal and pond environments. The purpose of this study was to determine the effect of the coastal and pond environment on the content of photosynthetic pigments and total phenol in the leaves of A. marina. The study was conducted using the observation method involving the location of the beach and ponds. The study used a Completely Randomized Design (CRD) with one factor of A. marina leaf organ that lives in the coastal and pond environment. The observation area are divided into 6 sampling points. Parameters observed were light intensity, temperature, salinity, photosynthetic pigments (chlorophyll a, chlorophyll b, carotenoids) and total phenol of A. marina leaves. Data analysis used T test with 95% confidence level. The results showed that the leaves of A. marina on the beach had lower photosynthetic pigments and total phenol content than those in ponds. This shows that the coastal environment and ponds have a significant effect on the content of photosynthetic pigments and phenols. Light intensity and high salinity on the beach interfere with the formation of chlorophyll and Phenylalanine Ammonia Lyase (PAL).

Rumput belulang (Eleusine indica (L.) Gaertn) merupakan gulma yang hidup di area pertanian. Pengendalian gulma dapat dilakukan dengan mengguanakan bioherbisida. Tanaman yang dapa dijadikan bioherbisida adalah tanaman yang mengandung alelokimia. Alelokimia adalah senyawa kimia yang dihasilkan tumbuhan dan apabila di keluarkan ke lingkungan mampu menghambat pertumbuhan tanaman disekitarnya Salah satu tanaman yang mengandung alelokimia adalah A. conyzoides. Penelitian ini bertujuan untuk mengetahui pengaruh alelokimia ekstrak daun A. conyzoides pada konsentrasi yang berbeda terhadap kandungan pigmen fotosintetik dan pertumbuhan gulma rumput belulang, serta mengetahui konsentrasi optimum yang dapat menghambat pertumbuhan rumput belulang. Penelitian ini menggunakan Rancangan Acak Lengkap (RAL) faktor tunggal yaitu konsentrasi ekstrak alelokimia A. conyzoides, masing – masing perlakuan dengan mengguanakan lima ulangan. Perlakuan dengan konsentrasi berbeda yaitu 0%, 5%, 10%, 15%. Parameter yang diamati yaitu kandungan klorofil a, klorofil b , klorofil total, karotenoid, bobot basah, bobot kering, tinggi tanaman, panjang akar, dan jumlah daun yang dianalisis dengan ANOVA dan dilanjutkan dengan Uji DMRT pada taraf kepercayaan 95%. Hasil penelitian ini menunjukkan bahwa semakin tinggi konsentrasi ekstrak memberikan pengaruh nyata terhadap penurunan kandungan klorofil a, klorofil b , klorofil total, karotenoid, bobot basah, bobot kering, tinggi tanaman, panjang akar, dan jumlah daun. Kata kunci : Rumput belulang, alelokimia, A. conyzoides, bioherbisida

Mustard plants are a type of vegetable favored by most people. Demand formustard plants continues to increase along with the increasing population and awareness of nutritional needs, but there are obstacles in increasing the production. This is due to the lack of nutrients needed by the mustard plant for its growth. One effort to increase the production of mustard plants is by adding nutrients through fertilization. Fertilizers are divided into two types, namely organic and inorganic fertilizers. However, long-term use of inorganic fertilizers can reduce soil quality and environmental health. One alternative to overcome these problems is to use liquid organic fertilizer in the form of fermented rice washing water. This study aims to determine the effect of 1-day fermented rice washing water and 15-days fermented rice washing water at different concentrations on photosynthetic pigment content and vegetative growth of green mustard plants and find out the best dose of rice washing water for the growth of green mustard plants. The study used a Completely Randomized Design (CRD) of 1 factor with 5 treatments. Each treatment with 4 replications with ordinary water as a control, 1-day fermented rice washing water with the concentration of 50% and 100%, and 15-days of fermented rice washing water with the concentration of 50%, and 100%. The results showed that the watering on 1-day fermented rice washing water with the concentration of 50% and 100% and 15-days of fermented rice washing water with a concentration of 50% had no effect on all parameters but the watering of 15-days fermented rice washing water with a concentration of 100% had an effect on increasing the plant height, number of leaves, leaf area, plant fresh weight, and plant dry weight. The growth of mustard green plants (Brassica juncea L) is best obtained in the treatment of 15-days fermented rice washing water with a concentration of 100%.

Rumput laut dan ekstraknya mengandung banyak senyawa kimia protektif yang berfungsi sebagai antioksidan, di antaranya senyawa fenol, dietary fiber, PUFA dan fotosintetik pigmen. Penelitian ini bertujuan untuk menentukan kandungan pigmen dan aktivitas antioksidan ekstrak rumput laut <em>Gracilaria salicornia, Turbinaria decurens</em> dan <em>Halimeda macroloba</em> yang diambil dari perairan Sulawesi Utara. Rumput laut diekstraksi menggunakan metode maserasi dengan pelarut aseton dan etanol. Analisis pada penelitian ini terdiri dari: klorofil a, klorofil b, total klorofil, klorofi C1+C2, fukoxantin, karotenoid, fikosianin dan fikoeritrin; kadar total fenol, aktivitas peredam radikal DPPH (1,1-diphenyl-2-picrylhydracyl) dan daya reduksi. Hasil analisis menunjukkan bahwa kandungan pigmen tertinggi adalah klorofil C1+C2 yang<br />terdapat pada ekstrak etanol <em>H. macroloba</em> (6,23016±0,12457 mg/g). Kadar total fenol tertinggi terdapat pada ekstrak aseton <em>G. salicornia</em> (72,224±6,01 µg GAE (Galic acid equivalent)/g. Aktivitas aktioksidan peredam radikal DPPH tertinggi adalah ekstrak etanol <em>T. decurens</em> (IC50 0,3033±0,023 mg/mL). Nilai daya reduksi tertinggi terdapat pada ekstrak aseton dan atanol H. macroloba dengan nilai masing-masing 0,248±0,014 dan 0,214±0,013 µM Fe2+/mg. Hal ini disimpulkan bahwa <em>G. salicornia</em>, <em>T. decurens</em> dekstrak dan H. macroloba dapat berfungsi sebagai pangan fungsional sumber pigmen dan antioksidan alami. <br /><br />

AbstrakC-fikosianin adalah senyawa pigmen-aksesori fotosintetik berwarna biru yang terkandung dalam sianobakteria. Jaaginema sp. BTM-11 merupakan sianobakteria laut yang memiliki potensi sebagai penghasil pigmen C-fikosianin karena kandungannya yang tinggi. Nilai ekonomis pigmen C-fikosianin sangat ditentukan oleh rasio kemurnian yang dimilikinya. Penelitian ini bertujuan untuk meningkatkan kemurnian pigmen C-fikosianin dari ekstrak sianobakteria laut Jaaginema sp. BTM-11 dengan menggunakan kitosan dan arang aktif. Variabel independen pada penelitian ini adalah konsentrasi kitosan (0,075-3,750 g/L) dan konsentrasi arang aktif (2,5-10 g/L). Toksisitas C-fikosianin diuji dengan menggunakan metode Brine Shrimp Lethality Test (BSLT) untuk mendapatkan nilai Konsentrasi Letal-50 (LC50). Penggunaan kitosan konsentrasi 0,3 g/L yang dilanjutkan dengan penggunaan arang aktif konsentrasi 5,0 g/L berhasil meningkatkan rasio kemurnian pigmen C-fikosianin sebesar 57,5 dan 167,5%, secara berturut-turut. Kapasitas pengikatan kitosan dan kapasitas penjerapan arang aktif secara signifikan berhasil meningkatkan kemurnian C-fikosianin dari awalnya 0,900±0,067 menjadi 2,408±0,171. Peningkatan rasio kemurnian C-fikosianin juga diikuti dengan peningkatan toksisitas fraksi C-fikosianin sianobakteria laut Jaaginema sp. BTM-11. Nilai LC50 ekstrak Jaaginema sp. BTM-11 sebelum pemurnian yang sebesar 15,75 ppm meningkat menjadi 12,06 ppm setelah dimurnikan dengan kitosan dan arang aktif. Enhancement of Purity and Toxicity of C-Phycocyanin Pigment Extracted from Marine Cyanobacteria Jaaginema sp. BTM-11 Using Chitosan and Activated CarbonAbstractC-phycocyanin is a blue colored accessory photosynthetic pigment found in cyanobacteria. Jaaginema sp. BTM-11 is marine cyanobacteria which is potential to be used as C-phycocyanin producer due to its high contents. The economical value of the blue pigment, C-phycocyanin, is determined by its purity. This research aimed to enhancing the purity of C-phycocyanin extracted from marine cyanobacteria of Jaaginema sp. BTM-11 using chitosan and activated carbon. The independent variables of this research were chitosan concentration (0.075-3.750 g/L) and activated carbon concentration (2.50-10.0 g/L). The toxicity test of C-phycocyanin was carried out using Brine Shrimp Lethality Test (BSLT) method to obtain the Lethal Concentration-50 (LC50) value. The application of 0.3 g/L chitosan continued by of 5.0 g/L activated carbon was successfully increased the purity of C-phycocyanin by 57.5 and 167.5%, respectively. Binding capacity of chitosan and adsorption capacity of activated carbon succeed to significantly increase the purity ratio of C-phycocyanin from 0.900±0.067 to 2.408±0.171. The enhancement of purity ratio of C-phycocyanin fraction extracted from Jaaginema sp. BTM-11 was also followed by the enhancement of its toxicity. LC50 of C-phycocyanin extract before purification (15.75 ppm) was lower compared to the C-phycocyanin fraction (12.06 ppm) after being treated with chitosan and activated carbon.

Caulerpa racemosa merupakan salah satu jenis rumput laut hijau (Chlorophyta) yang memiliki pigmen fotosintetik klorofil-a dan klorofil-b. Pigmen tersebut labil terhadap suhu dan cahaya. Tujuan penelitian ini adalah mengetahui pengaruh suhu dingin (9oC) dan suhu ruang (29oC) terhadap stabilitas ekstrak kasar pigmen klorofil dengan lama penyimpanan 7 hari. Metode yang digunakan pada penelitian adalah eksperimental laboratoris. Rancangan penelitian yang digunakan adalah Rancangan Acak Lengkap (RAL) faktorial dengan 2 faktor yaitu suhu (9oC, 29oC) dengan interval pengujian (1, 3, 5, 7 hari). Ekstraksi dilakukan dengan metode maserasi dengan pelarut ethanol 96%. Parameter yang diamati berupa konsentrasi klorofil-a, klorofil-b, kecerahan ekstrak dan pH. Hasil penelitian menunjukkan konsentrasi klorofil-a, klorofil-b, dan pH menurun sedangkan kecerahan ekstrak meningkat setelah disimpan selama 7 hari baik pada suhu dingin maupun suhu ruang. Penurunan tertinggi konsentrasi klorofil-a sebesar 1,32 mg/g, klorofil-b sebesar 2,09 mg/g dan nilai pH sebesar 6 pada penyimpanan suhu ruang, penyimpanan pada suhu dingin mengalami penurunan terendah dengan konsentrasi klorofil-a sebesar 1,42 mg/g, klorofil-b sebesar 2,21 mg/g dan nilai pH sebesar 6,2. Nilai kecerahan ekstrak mengalami kenaikan tertinggi pada penyimpanan suhu ruang sebesar 30,99, sedangan terendah pada suhu dingin sebesar 29,25. Caulerpa racemosa is a one kind of green seaweed (Chlorophyta) which has photosynthetic pigment chlorophyll-a and chlorophyll-b. The pigment is unstable with temperature and light. The purpose of this research is to find out the effect of cold temperature (9oC) and room temperature (29oC) on the stability of crude extract of C. racemosa chlorophyll pigment with a storage time of 7 days. This research was using an experimental laboratory method. The research design was used factorial Completely Randomized Design (CRD) with 2 factors, temperature (9oC, 29oC) days with interval testing on (1, 3, 5, 7 days). The Extraction was carried out by the maceration method with 96% ethanol as solvent. The observed parameters were concentration of chlorophyll-a, chlorophyll-b, extract brightness, and pH. The results showed that content of chlorophyll-a, chlorophyll-b, and pH had decreased with an increase in the brightness of the extract after being stored for 7 days at cold and room temperature. The higher decrease on content of chlorophyll-a by 1,32 mg/g, chlorophyll-b by 2,09 mg/g, and pH value of 6 when stored at room temperature, while in cold storage has the lowest decrease content of chlorophyll-a by 1,42 mg/g, chlorophyll- b by 2,21 mg/g and pH value by 6,2. The brightness value of the extract has the biggest increased at room temperature storage by 30,99 and the lowest is on the cold temperature by 29,25.

Abstrak Mikroalga merupakan mikroorganisme fotosintetik prokariotik atau eukariotik yang dapat tumbuh dengan cepat. Pemanfaatan mikroalga tidak hanya berorientasi sebagai pakan alami untuk akuakultur, tetapi terus berkembang untuk bahan baku produksi pakan ternak, pigmen warna, bahan farmasi (β-carotene, antibiotik, asam lemak omega-3), bahan kosmetik, pupuk organik, dan biofuel (biodiesel, bioetanol, biogas, dan biohidrogen. Studi ini bertujuan untuk menginvestigasi kombinasi ultrafiltrasi (UF) – dissolved air flotation (DAF) untuk pemekatan mikroalga skala laboratorium. Hasil penelitian menunjukkan bahwa penurunan fluks membran UF secara tajam sebagai akibat dari deposisi sel mikroalga terjadi pada 20 menit pertama proses filtrasi. Backwash pada interval 20 menit selama 10 detik dengan tekanan 1 bar memberikan pengendalian fouling yang efektif dalam nilai kestabilan fluks yang layak. Membran UF yang digunakan dapat memberikan selektivitas pemisahan biomassa mikroalga ~ 100%. Kualitas permeat sangat stabil, yaitu kekeruhan < 0,5 NTU, kandungan organik < 10 mg/L, dan warna < 10 PCU. Lebih lanjut, pemekatan retentat membran dengan DAF pada tekanan saturasi 6 bar dapat menghasilkan pasta mikroalga dengan konsentrasi 20 g/L. Koagulan PAC perlu ditambahkan kedalam umpan DAF dengan dosis 1,3–1,6 mg PAC/mg padatan tersuspensi. Kata Kunci: ultrafiltrasi; dissolved air flotation; pemanenan mikroalga; pemekatan mikroalga Abstract COMBINATION OF Ultrafiltration and Dissolved Air Flotation for Microalgae CONCENTRATION. Microalgae is a prokaryotic photosynthetic microorganism or eukaryotic microorganism that proliferate rapidly. Cultivation of the microalgae is not only oriented as natural food for aquacultures, but also developed for animal food, color pigment, pharmaceutical raw material (β-carotene, antibiotic, fatty acid omega-3), cosmetic raw material, organic fertilizer, and biofuels (biodiesel, bioethanol, biogas, and biohydrogen. This study is aimed to investigate the potential of combination of ultrafiltration (UF) and dissolved air flotation (DAF) for concentration of microalgae in laboratory scale. The experimental results showed that fluxes of the UF membrane decreased sharply due to deposition of microalgae biomass during first 20 minutes of filtration. Periodically backwash using the UF permeate (backwash interval = 20 minutes; backwash duration = 10 seconds; backwash pressure = 1 bar) gave an effective fouling control to maintain reasonable stable fluxes. In addition, the UF membrane gave separation of microalgae biomass ~ 100%. Permeate quality is strongly stable in which turbidity < 0.5 NTU, organic content < 10 mg/L, and color < 10 PCU. Moreover, concentration of the UF retentate by DAF under saturation pressure of 6 bars was able to produced microalgae feedstock having 20 g/L dry microalgae. PAC is required for DAF feed with dosage of 1.3–1.6 mg PAC/mg suspended solids.

Because its oxidative power, tropospheric ozone is considered, at the large scale, the most harmful pollutant to vegetation. The exceedances of critical levels set to protect vegetation are quite high and widespread, so that large parts of crops and forests in Europe are exposed to potentially harmful levels of ozone. The impact of ozone on vegetation is the result of multiple factors such as the concentration in the atmosphere, the stomatal uptake - which depends on environmental and physiological factors -, and the detoxification potential of plants. The complexity of these factors and their interactions can make it difficult to establish a clear relationship between ozone and plant response under field conditions. The use of plants as bioindicators may be a solution because they reflect and summarize all processes that occur between ozone exposure and the response of the plant. The aim of this research is to explore the potential of the shrub species Viburnum lantana L. as a bioindicator in situ to assess the potential effects of ozone on native vegetation. This species is known to be sensitive to ozone, has a specific response (visible foliar injuries, consisting in red stipples on the upper leaf surface ), and a wide spatial distribution. However it is not fully known if V. lantana meets all the requirements to be used as a bioindicator. In particular, the actual responsiveness to ozone of native plants and the relationship between the intensity of responses and the levels of exposure to the pollutant under field conditions remain to be evaluated. For these purposes, two field studies were carried out in the Province of Trento (North Italy) at local (1) and large scale (2). Moreover, a study under controlled conditions (3) was carried out in order to deepen the knowledge about the effects of ozone on V. lantana at biochemical, physiological and genetic level. (1) The first study was carried out in 2009 and aimed at assessing the time course of plant responses to ozone during the growing season. To this, two 1x1 km quadrates were considered. The two quadrates, located 3 km apart, were characterized by different levels of ozone. The adoption of a completely randomized experimental design ensured replication in each area and the selection of plants. Plants were monitored for the development of ozone-specific foliar symptoms, the chlorophyll content (SPAD) and the fluorescence of chlorophyll a during the entire growing season. (2) The second study was carried out in 2010 and aimed at verifying the response of V. lantana to different levels of ozone exposure. To this end, a stratified random sampling design (elevation x ozone) was adopted to select 30 1x1 km quadrates. On all quadrates, the assessment of symptomatic plants was carried out. For this second field study, the spatial domain was the entire surface of the province of Trento (6.200 km2). (3) For the study in controlled environment, 9 potted plants of V. lantana were subjected to fumigation with known concentrations of ozone (60 ppb for 45 days, 5 hours per day) (treated), while other 9 plants were maintained under the same environmental conditions with the exception of ozone (control). Plants were analyzed for the presence and development of foliar symptoms, chlorophyll content (SPAD), fluorescence of chlorophyll a, leaf content of photosynthetic pigments and carbohydrate (HPLC) and gene expression. Overall, the results of the two field studies allowed to verify (1) a temporal development of the responses of V. lantana consistent with the trend of ozone exposure; and (2) an higher frequency of symptomatic plants where ozone levels were also higher. However, the frequency of symptoms was not always proportionate to the level of ozone exposure. At the same time of the onset and spread of foliar symptoms, a decrease in the foliar chlorophyll content and in photosynthetic performance occurred. The analysis of the fluorescence transient of chlorophyll a showed an early response to ozone for the parameter ΔVI-P, that indicates the ability of the final electron acceptor to be reduced. Interestingly, when comparing similar ranges of ozone exposures, symptomatic plants were always more frequent at higher altitudes (above 700 m a.s.l.): this may suggests that they are subjected to an additional oxidative stress (e.g. due to solar radiation), and/or that environmental conditions are more favourable to ozone uptake (high relative humidity and relative lower temperature). The physiological and metabolic analysis carried out on plants treated with ozone, confirmed their reduced photosynthetic capacity and their lower content of chlorophyll, as well as a not completely effective system to protect plants against photo-inhibition. This behavior is probably the cause of the sensitivity of this species in relation to the ozone. V. lantana - whose sensitivity and specificity of response to ozone were verified also in real field conditions - seems suitable as a bioindicator in situ to qualitatively assess the potential impact of ozone, for large-scale surveys and in remote areas. Foliar symptoms on this species are also confirmed as valid response indicators of ozone, although their interpretation in terms of potential damage to vegetation always requires great caution.

In this study experiments were conducted on the influence of ½ Hoagland nutrient media (NM), utilized for germination, on the content of chlorophylls, carotenoids and activity of photosystem II (FSII) of two maize hybrids (Porumbeni 180 and Bemo 203). The results showed that contents of chlorophyll a, b, (a + b) and carotenoids were significantly higher in leaves of Bemo 203 that germinated on NM, compared to the control. But in leaves of the Porumbeni 180 hybrid significant differences in the content of chlorophyll pigments in both the control and exper-imental plants were not detected. The FSII level in the leaves of the Porumbeni 180 was higher than in leaves of the Bemo 203, both for the control and experimental plants.

Žemės ūkio sektoriui tenka svarbus vaidmuo įgyvendinant Europos Sąjungos žaliojo kurso tikslus. Gausiai naudojant sintetines ir organines trąšas, gamtiniuose vandenyse pastebimas nitratų koncentracijos didėjimas. Dideli kie-\kiai trąšų išplaunama į vandenis, o tai visų pirma skatina spartų ir perteklinį vandens dumblių ir melsvabakterių žydėjimą upėse, ežeruose ir galiausiai jūrose. Todėl, dirbant nuosekliai ir deramai kontroliuojant miesto valymo įrenginius, buiti- nes, pramonines bei žemės ūkio nuotekas, taip pat siekiant kiek įmanoma atsisakyti sintetinių trąšų naudojimo žemės ūkyje, galima tikėtis šį nepageidautiną procesą suvaldyti. Fitoplanktono biomasės, kaip žaliosios trąšos, naudojimo galimybės mažai tyrinėtos. Eksperimentiniams tyrimams atlikti buvo pasirinkti trys dažniausiai Lietuvoje sėjamų žemės ūkio augalų – paprastasis kvietys (Triticum aestivum L.), sėjamasis žirnis (Pisum sativum L.) ir sėjamasis rapsas (Brassica na- pus L.). Į augalų augimo substratą buvo įterpti skirtingi liofilizuotos fitoplanktono biomasės, surinktos iš Kuršių marių, kiekiai. Norint įvertinti fitoplanktono, kaip sintetinių trąšų alternatyvos, poveikį analizuotų augalų augimo ir vystymosi procesams, buvo atlikta biometrinių parametrų – antžeminės augalo dalies aukščio, žaliosios ir sausosios masės pokyčių analizė, taip pat fotosintetinių pigmentų – chl a, chl b kiekio ir chl a ir b santykio ir karotinoidų kiekio analizė. Tyrimai parodė, kad, sprendžiant vandens kokybės problemos gerinimo klausimus, surinktoji perteklinė fitoplanktono biomasė, kaip biostimuliatorius, gali būti naudojama augalininkystėje, taip pat skatinant alternatyvius tręšimo būdus ir mažinant sintetinių trąšų naudojimo mastą žemės ūkyje.