Organic onion growth, yield and storage improved by foliar sprays of microalgae and fulvic acid as a natural biofertilizer

The use of microalgae as natural biofertilizer in horticulture has recently been reported, while the use of humic substances is widespread. However, the combined use of microalgae with humic substances applied to plant leaves is still unexploited. Thus, the objective of this work was to combine fulvic acid (FA) with the Scenedesmus subspicatus microalga biomass (SC) as a natural biofertilizer applied via leaf in two onion cultivars in organic system. Four experiments were conducted: i) bioassays to verify the bioactive effect of FA, SC and combinations using the Vigna radiata model plant; ii) greenhouse pot experiment with foliar applications of FA, SC and combination in two onion cultivars; iii) field experiment in organic system with foliar applications of FA, SC and combination in two onion cultivars; and iv) onion bulb storage experiment. The bioactive effect of SC, FA and their combinations was identified by promoting changes in root growth of V. radiata. In pots, treatments containing FA, SC and combination promoted increase in fresh and dry leaf mass. The foliar application of FA, SC and combination promoted an increase in field bulb productivity, reduced mass loss in stored bulbs and increased carbohydrate, amino acid and protein contents in onion bulbs.

Biofuel production potential of indigenous isolates of Scenedesmus sp. from lake water in Pakistan

Aims@#This paper presents the report on biodiesel and biogas production at a laboratory scale from Scenedesmus strain.@*Methodology and results@#Previously isolated and identified Scenedesmus were grown in 10 Liter flask using BG-11 media at 16 h light and 8 h dark cycle. Oven-dried biomass (20 g) from 16-day-old culture of Scenedesmus was finely grounded and subjected to lipids extraction by chloroform-methanol-NaCl mixture. Microalgal lipids (6 mL) were subjected to transesterification by using NaOH leading to the production of 5 mL biodiesel and 4 mL of glycerin. Biodiesel was rich in methyl esters of linoleic acid, phosphorothioc acid and dodecanoic acid, as shown by gas chromatography-mass spectrometry (GC-MS) analysis. Oven-dried microalgae (2 g) without lipid extraction and leftover biomass (2 g) after lipid extraction were subject to biogas production through anaerobic digestion. Biogas (34, 27 and 19 mL) were recorded respectively in oven-dried whole biomass; lipid extracted biomass and control over a period of 15 days of anaerobic digestion.@*Conclusion, significance and impact of study@#It was concluded that water bodies are rich in diverse algae, especially Scenedesmus sp., and this algae can be cultured to produce biodiesel and biogas. But the lipid accumulation potential of microalgae requires special treatment and lipid extraction methods are not up to the mark, which is a major bottleneck in biofuel production from microalgae.

The nutraceutical effect of Scenedesmus dimorphus for obesity and nonalcoholic fatty liver disease–linked metabolic syndrome

Obesity is a major cause of nonalcoholic fatty liver disease (NAFLD), which is identified as a characteristic relatedto metabolic syndrome. This study focuses on the benefits of Scenadesmus dimorphus as a nutraceutical to overcomeNAFLD-linked metabolic syndrome caused by obesity. The research used 30 mice (Mus musculus) divided into sixgroups: normal control, obesity control (OC), and drug control (Orlistat) and S. dimorphus administrated orally for21 days in obese mice with NAFLD-linked metabolic syndrome with doses of 5 mg/20 g body weight (BW), 10mg/20 g BW, and 15 mg/20 g BW. The administration of a high-fat diet can cause obese mice to suffer from NAFLD,resulting in an increase in liver enzymes and changes in lipid metabolism. Administration of S. dimorphus at 15mg/20 g BW decreases the activity of liver enzymes and improves liver function. The statistics test showed significantdifferences (p < 0.05 analysis of variance) to decrease the liver enzyme activity of alanine aminotransferase, aspartateaminotransferase, and alkaline phosphatase compared to OCs. Administration of S. dimorphus resulting in metabolismchanges showed a significant (at p < 0.05) decrease in total cholesterol, triglycerides, and low-density lipoproteincholesterol and increased high-density lipoprotein cholesterol. Microalgae S. dimorphus is beneficial as a nutraceuticalto manage obesity and reverse NAFLD-linked metabolic syndrome in obese mice.

Removal of COD, BOD and nutrients in swine manure wastewater using freshwater green microalgae

@#Aims:The aim of this study was to investigate the effectiveness of freshwater green microalgae in remediating swine manure wastewater. Two different species of freshwater green microalgae (Scenedesmus quadricaudaand Stigeocloniumsp.) were used in this study.Methodology and results:Laboratory experiments were performed to compare the growth rate and nutrients (total phosphorus, ammonia nitrogen, nitrate nitrogen and nitrite nitrogen) uptake by these two species of microalgae in swine manure wastewater. Experimental work was carried out for 14 days at room temperature of 30±1 °C with about 1520 Lux of light intensity. The results showed that both microalgae grew well in swine manure wastewater. S.quadricaudaperformed better in remediating swine manure wastewater, by reducing 83.99% of COD, 80.39% of BOD5, 84.78% of total phosphorus (TP), 91.79% of ammonia nitrogen (NH3-N), 89.79% of nitrate nitrogen (NO3-N) and 87.14% of nitrite nitrogen (NO2-N) compared to Stigeocloniumsp. which was only able to remove 79.26% of COD, 76.27% of BOD5,75.17% of TP, 86.42% of NH3-N, 84.38% of NO3-N and 82.38 NO2-N.Conclusion, significance and impact of study:The results of this study indicate that these two species of microalgae have potential to be used in the remediation of swine manure wastewate

Post-treatment of palm oil mill effluent (POME) using freshwater green microalgae145-

@#Aims:The effectiveness of microalgae in the post-treatment of palm oil mill effluent (POME) was being investigated for colourremoval and COD reduction. Methodology and results:Raw POME, obtained from a local palm oil mill and treated with anaerobic and aerobic processes for 50 days and 16 days of hydraulic retention time (HRT) respectively, was then used in the phycoremediation study. Three different species of microalgae (Ankistrodesmus falcatus, Scenedesmus sp. and Chlorellasp.) were inoculated in a culture media which contained 20%, 40% and 60% dilution of POME. The pH of thetreated POME sample was not adjusted and fixed at the original pH of about pH 8-9. The growth of the microalgae was determined every 2 days based on their chlorophyll concentration. Chlorellasp. showed the best adaptation and grew well in all dilutions of the treated POME sample and subsequently chosen for remediation of the POME sample without any dilution.Conclusion, significance and impact of study:Chemical oxygen demand (COD) and colour removal of POME were determined every 2 days. Chlorellasp. performed well with COD reduction and colour removal of 67.87% and 53.26%, respectively.

Study of medicinal properties of Arisaematis Rhizoma Preparatum and Arisaema Cum Bile based on delayed luminescence of Scenedesmus sp / 中草药

Objective To find delayed luminescence parameters that could characterize the cold and hot properties of Arisaematis Rhizoma Preparatum and Arisaema Cum Bile. Methods Delayed luminescence of Arisaematis Rhizoma Preparatum with addition of Scenedesmus sp. within 26 d after decoction was measured in unequal interval, with aim to verify the stability of the natural delayed luminescence average strength and the linear fitting slope value (k) of excitation delayed luminescence. The delayed luminescence of six batches of Arisaematis Rhizoma Preparatum and Arisaema Cum Bile was measured using biological indicator method, and the content of β-sitosterol in Arisaematis Rhizoma Preparatum and β-sitosterol, bilirubin, and cholic acid of Arisaema Cum Bile was determined using high performance liquid chromatograph (HPLC) to analyze the correlation of k value and the above components content of Arisaematis Rhizoma Preparatum and Arisaema Cum Bile. Results K value of excitation delayed luminescence within 14 d after decoction was steadier than natural delayed luminescence average strength, and k values of six batches of Arisaematis Rhizoma Preparatum were all higher than that of Arisaema Cum Bile. A significant negative correlation between β-sitosterol contents and k values of six batches of Arisaematis Rhizoma Preparatum and Arisaema Cum Bile was found, and no significant negative correlation between bilirubin and cholic acid contents and k values of Arisaema Cum Bile was found. Conclusion K value of excitation delayed luminescence could indicate the differences of medicinal properties of Arisaematis Rhizoma Preparatum and Arisaema Cum Bile, which provides a new method for the study of medicinal properties of Chinese materia medica.

MEDICIÓN DE LA FLUORESCENCIA DE LA CLOROFILA a EN ALGAS ENCAPSULADAS EN ALGINATO DE CALCIO / Measuring of the Chlorophyll a Fluorescence in Calcium Alginate-Encapsulated Algae

RESUMEN La inmovilización de las algas tiene múltiples aplicaciones, tales como la biorremediación del agua y la producción de metabolitos. Una de las variables que se puede determinar en las algas inmovilizadas es la fluorescencia de la clorofila a, debido a que este parámetro está relacionado con la respuesta fisiológica de estos organismos. Por ello, el objetivo de este estudio fue explorar un método para la medición de la fluorescencia de la clorofila a en algas encapsuladas en esferas de alginato de calcio. Con este fin, se cultivaron dos especies de microalgas (Scenedesmus ovalternus LAUN 001 y Parachlorella kessleri LAUN 002) en monocultivos, tanto en condiciones de cultivo libres (10 mL de la preparación algal en 250 mL de Medio Básico de Bold), como encapsuladas (250 esferas de alginato de calcio en 250 mL de Medio Básico de Bold). Se realizaron diferentes protocolos de medición de la fluorescencia de la clorofila a del fotosistema II (PSII) variando a) el tiempo de preadaptación a la oscuridad (10, 15 y 30 min), b) la intensidad de luz generada por fluorómetro no modulado (entre 1000 y 3500 -jmoles m-2 s-1), y c) el tiempo de exposición a la luz actínica (1, 2 y 5 s). Se lograron establecer como condiciones óptimas para la medición de la eficiencia cuántica potencial del fotosistema II (Fv/Fm) en las algas encapsuladas las siguientes: a) 30 min de preadaptación a la oscuridad; b) 3000 -jmoles m-2 s-1, de intensidad lumínica generada desde el fluorómetro; y c) 1 o 2 s de exposición a la luz actínica. Se encontraron los siguientes valores en la Fv/Fm en condiciones no estresantes: 0,760 a 0,764 para S. ovalternus y 0,732 a 0,748 para P. kessleri. Esta metodología permite observar algunos cambios en la actividad fotoquímica relacionados con variaciones de los factores bajo los cuales se encuentran las algas inmovilizadas.

ABSTRACT Immobilization of algae has many applications, such as water bioremediation and production of metabolites. One of the variables that can be determined in the immobilized algae is chlorophyll a fluorescence, because this parameter is related to the physiological response ofthese organisms. Therefore, the objective ofthis study was to explore a method for measuring the chlorophyll a fluorescence in calcium alginate-encapsulated algae. To do this, two species of microalgae (Scenedesmus ovalternus LAUN 001 and Parachlorella kessleri LAUN 002) were grown in monocultures in both free culture conditions (10 mL of algae preparation in 250 mL of Basal Bold Medium) and encapsulated (250 spheres in 250 mL of Basal Bold Medium). Different measurement protocols of chlorophyll a fluorescence of photosystem II (PSII) were performed by varying a) the preadaptation time to darkness (10, 15 and 30 min), b) the light intensity of the non-modulated fluorometer (between 1000 and 3500 Llmoles m-2s-1), and c) the time of exposure to actinic light (1, 2 and 5 s). The optimal conditions for the measurement of the maximum quantum yield ofPSII (Fv/Fm) in encapsulated algae were established as follow: a) 30 min of preadaptation time; b) 3000 Llmoles m-2s-1 of the fluorometer light intensity; and c) 1 to 2 s of exposure to actinic light. The following values in the photochemical activity of algae in non-stressful conditions were found: 0.760 - 0.764 for S. ovalternus, and 0.732 - 0.748 for P. kessleri. This methodology allows to observe some changes in the photochemical activity related with variations in the factors under which are the immobilized algae.

Influence of light intensity, temperature and CO2 concentration on growth and lipids in green algae and cyanobacteria.

Effects of the environmental variables such as light intensity (µmol photons m-2s-1), temperature (°C) and CO2 concentration (ppm) on chlorophyll, total soluble proteins and lipids were studied in selected microalgal strains from Chlorophyceae (Chlamydomonas sp., Scenedesmus sp., Chlorella sp., Kirchneriella sp.) and cyanobacteria (Nostoc sp.1, Anabaena sp., Nostoc sp. 2, Cylindrospermum sp.). Cultures were grown under controlled conditions at the National Phytotron Facility, Indian Agricultural Research Institute (IARI), New Delhi. Our results showed that chlorophyll concentration enhanced with increased CO2. Chlorella exhibited the highest chlorophyll at 850 ppm CO2 and 28°C; for Chlamydomonas it was at 78 µmol photons m-2s-1 light intensity. In Cylindrospermum, total soluble proteins decreased with enhanced CO2, and were highest at 18°C. In Anabaena, a light intensity of 65 µmol photons m-2s-1 was best for maximum total soluble proteins. In Chlorella, CO2 @ 850 ppm was most suited for maximum lipid accumulation. In Kirchneriella, increase in temperature, from 18°C up to 37°C, increased total lipids; the highest was at 28°C. In Chlamydomonas, the light intensity of 78 µmol photons m-2s-1 was optimum for lipid accumulation and the maximum total lipids was 30.8 (% dry wt.).

INMOVILIZACIÓN DE LAS MICROALGAS Scenedesmus ovalternus (Scenedesmaceae) Y Chlorella vulgaris (Chlorellaceae) EN ESFERAS DE ALGINATO DE CALCIO / Immobilization of Microalgae Scenedesmus ovalternus (Scenedesmaceae) and Chlorella vulgaris (Chlorellaceae) in Calcium Alginate Beads

En este trabajo se describe la técnica de inmovilización de microalgas en esferas de alginato de calcio. Se emplearon las especies Scenedesmus ovalternus y Chlorella vulgaris, se determinó la estabilidad de las esferas, la cinética de crecimiento y la concentración de las microalgas en el interior de las esferas. Chlorella vulgaris alcanzó mayores densidades poblacionales y tasas de crecimiento más altas cuando se inmovilizó en concentraciones del 10 % v/v con el alginato (1,31*10(6) cél/ml). Para Scenedesmus ovalternus se observó una mayor densidad poblacional y una mayor tasa de crecimiento cuando se inmovilizó en concentraciones del 20 % v/v (7,06*10(5) cél/ml). Estos resultados son útiles para aplicaciones prácticas de las algas encapsuladas, tales como el biomonitoreo o la biorremediación.

This paper describes the immobilization technique of microalgae in calcium alginate beads. Scenedesmus ovalternus and Chlorella vulgaris species were used. The stability of beads, the kinetics of growth and the concentrations of microalgae inside the beads were determined. The higher density and the upper growth rate of Chlorella vulgaris occurred when it was immobilized in alginate at a concentration of 10 %v/v (1,31*10(6) cél/ml). Scenedesmus ovalternus achieved a higher population density and an elevated growth rate when it was immobilized at a concentration of 20 % v/v (7,06*10(5) cél/ml). These results are useful for subsequent applications of the encapsulated algae, such as biomonitoring and bioremediation.

Cultivation of Scenedesmus dimorphus for C/N/P removal and lipid production

Background CO2 emission, water pollution and petroleum shortage are the issues coming with the development of industry. A cost effective system was constructed to fix the CO2 in flue gas (15% CO2), remove nitrogen and phosphorus from manure wastewater and produce biofuels at the same time. The significant cultivation conditions were selected by Plackett-Burman design, and then optimized with central composite design. Results Optimum culture condition was predicted at light intensity of 238 µmol·m- 2·s- 1, TN of 152 mg·L- 1, inoculum density of 0.3 g·L- 1, under which the measured CO2 fixation rate, total nitrogen and phosphorus removing rate, and lipid content were 638.13 mg·L- 1·d- 1, 88.16%, 73.98% and 11.9%, respectively. The lipid content was then enhanced to 24.2% by a nitrogen starvation strategy. Conclusion A cultivation strategy was suggested to achieve effective C/N/P removal from flue gas and manure wastewater, and meanwhile obtained high lipid content from microalgal biomass.

Growth of microalgae Scenedesmus sp in ethanol vinasse

This study evaluated the feasibility of using vinasse as a nutrient source for microalgae cultivation. The Scenedesmus sp was grown in a medium supplemented with vinasse and process variables were optimized using a factorial design and a Central Composite Design (CCD). The factorial design results showed that it was possible to cultivate microalgae at concentrations of up to 40% of vinasse in the culture medium. The CCD results showed that the light intensity and vinasse concentration influenced the amount of biomass produced.

An experimental investigation on growth stimulation (+) and inhibition (-) of algae (oscillatoria.chlorina and scenedesmus.quadricauda) treated with pulp and paper mill effluents.

The growth stimulation (+) and inhibition (-) of algae treated with pulp and paper mill effluent was investigated in laboratory culture condition. The result revealed that the effect of paper mill effluent on algae was species specific. Effluents were stimulatory as well as inhibitory to the growth of test algae . Oscillatoria chlorina tolerated higher concentration where as Scenedesmus quadricauda tolerated lower concentration of effluent. At 100% effluent concentration growth was retarded and inhibition was the result. During investigation significant algal growth was observed between concentration and treatment days of which 21 days incubation period was considered as final yield.

The effect of temperature and body size on filtration rates of Limnoperna fortunei (Bivalvia, Mytilidae) under laboratory conditions

The golden mussel (Limnoperna fortunei, Mollusca: Bivalvia) is an invasive species that has been causing considerable environmental and economic problems in South America. In the present study, filtration rates of L. fortunei were determined in the laboratory under different temperatures (10, 15, 20, 25, 28, and 30 ºC) and two types of food (Algamac-2000® and the chlorophycean alga Scenedesmus sp.). There was a statistically significant relationship between time and filtration rates in the experiment using Scenedesmus sp., regardless of temperature. However, this pattern was absent in the experiment using Algamac, suggesting that the relationship between filtration rates and temperature might depend on the size of the filtered particles. In addition, there was no correlation between filtration rates and either shell size or condition index (the relationship between the weight and the length of a mussel). The filtration rate measured in the present study (724.94 ml/h) was one of the highest rates recorded among invasive bivalves to date. Given that the colonies of the golden mussel could reach hundreds of thousands of individuals per square meter, such filtration levels could severely impact the freshwater environments in its introduced range.

Perfil de ácidos graxos de microalgas cultivadas com dióxido de carbono / Fatty acids profile of microalgae cultived with carbon dioxide

As microalgas são consideradas fontes potenciais de diversos compostos químicos. Os ácidos graxos obtidos da biomassa podem apresentar efeitos terapêuticos em humanos e podem ser usados para produção de biodiesel. Objetivou-se, neste trabalho verificar o conteúdo lipídico e o perfil dos ácidos graxos das microalgas Spirulina sp., Scenedesmus obliquus, Chlorella kessleri e Chlorella vulgaris cultivadas em diferentes concentrações de dióxido de carbono e bicarbonato de sódio. A microalga Chlorella kessleri cultivada com 12 por cento de CO2 apresentou a maior concentração de lipídios na biomassa seca (9,7 por cento p/p). A máxima concentração de ácidos graxos insaturados foi 72,0 por cento (p/p) para C. vulgaris cultivada com 12 por cento de CO2. Para os ácidos graxos saturados o maior valor encontrado foi 81,6 por cento (p/p), quando a microalga Spirulina sp. foi cultivada com 18 por cento de CO2 e 16,8 g.L-1 de bicarbonato de sódio.

Microalgae have a great potential as a source of several chemical compounds. The fatty acids have shown therapeutic effects and used to produce biodiesel. The aim of this work was to verify the lipid contents and the fatty acids profile of the microalga Spirulina sp., Scenedesmus obliquus, Chlorella kessleri and Chlorella vulgaris cultived in different carbon dioxide and sodium bicarbonate concentrations. The microalgae Chlorella kessleri cultived with 12 percent CO2 showed the highest lipid content in the dry biomass (9.7 percent p/p). The maximum unsaturated fatty acids concentration was 72.0 percent (p/p) to C. vulgaris in the culture with 12 percent CO2. The highest saturated fatty acids value was 81.6 percent (p/p) when microalga Spirulina sp. was cultived with 18 percent CO2 and 16.8 g.L-1 sodium bicarbonate.

Immediate effects of pyridazinone herbicides on photosynthetic electron transport in algal systems.

Pyridazinone herbicides, SANDOZ 9785 (4-chloro-5-dimethylamino2-phenyl- 3-(2H) pyridazinone), SANDOZ 9789 (4-chloro-5 (methylamino)-2-(α, α, α-trifluoro-m-tolyl- 3-(2H) pyridazinone) and SANDOZ 6706 (4-chloro-5-(methylamino)-2-(α, α, α-trifluoro-mtolyl- 3-(2H) pyridazinone) inhibited photosystem II electron transport in Chlorella protothecoides, when the herbicides were added to the assay medium. The inhibitory eficiency varied with the algal species and the nature of substitution of pyridazinones. Using 3 algal systems viz., Chlorella, Scenedesmus and Anacystis, the I50 value of for the inhibition of photosynthesis of 3 substituted pyridazinones (SANDOZ 9785, SANDOZ 6706 and SANDOZ 9789) were determined. SANDOZ 9789 was found to be the weakest inhibitor of photosystem II electron transport (H2Ο→ benzoquinone) as compared to SANDOZ 9785 and SANDOZ 6706. In general, the order of inhibition could be given as SANDOZ 6706 > SANDOZ 9785 > SANDOZ 9789. The I50 value of photosynthetic particles obtained from Chlorella cells was similar to that of whole cells, suggesting that the cell wall of Chlorella did not act as a barrier for the herbicide action. Studies on the light intensity dependence of SANDOZ 9785 inhibition of electron transport (H2O→ benzoquinone) showed that the light-dependent portion of the curve was more sensitive than the light independent portion of the curve. It is suggested that the site of action was on the reducing side of photosystem II.

Microbial load in mass cultures of green algae Scenedesmus acutus and its processed powder.

Microbial contamination in cultures of the alga, Scenedesmus acutus raised in outdoor open tanks and also in the processed powder of the alga was monitored; The total bacterial population increased with time during the growth period of six days. When a combination of molasses and carbondioxide was employed as carbon source for this alga, the bacterial load increased to 10 colony forming units/ml. Yeast, molds and also coliforms were quantitated. Drum-drying the algae drastically reduced the bacterial load and storing the algal powder for a period of over 3 months did not increase the bacterial load. Pathogens like Salmonella and Staphylococcus were not detectable either in the open cultures or in the drumdried algal powder. Although there are not set standards available in literature on the permissible level of the microbial contamination in algal biomass for use in foods, the microbial load appears to be within the limits of permissible levels stipulated by Indian Standard Institution standards for baby foods.