Chlorella across latitudes: investigating biochemical composition and antioxidant activities for biotechnological applications

With the present day rise of interest in acquiring sustainability in the pharmaceutical industry,there has been an emphasis on finding natural resources to replace the use of synthetic compounds used in products.Microalgae have garnered significant attention owing to their natural and sustainable capability to produce a diverse array of bioactive compounds.Therefore,this study aims to evaluate the biochemical composition and antioxidant properties of Chlorella strains from a tropical region(Chlorella UMACC 051 and Chlorella UMACC 038)and a polar region(Chlorella UMACC 250 and Chlorella UMACC 234).The cultures were grown for 10 d.At the end of the experiment,the specific growth rate,chlorophyll-a content,carotenoid content,biomass,and biochemical composition such as carbohydrate,protein and lipid content were determined.In addition,the phytochemical properties were determined using a total phenolic assay while the antioxidant activities were determined using 2,2-diphenyl-1-picrylhydrazyl(DPPH).Of all Chlorella strains tested,the tropical Chlorella UMACC 051 showed the fastest growth rate and biomass while the polar Chlorella UMACC 234 contained the highest pigment content and tropical Chlorella UMACC 038 has the highest total phenolic content.The biochemical composition analysis showed all strains have a high lipid content ranging from 45.36%to 60.30%dry weight.All Chlorella strains exhibited a small amount of antioxidant activity(15.42%to 30.15%)and total phenolic content ranging from 1.91±0.04 to 4.43±0.10 mg GAE·g–1 dry weight.The results indicated that polar Chlorella UMACC 234 has the most potential in containing significant amounts of bioactive compounds.

Study of effects of environmental factors on biochemical compositions of four species of marine single-celled algae

Photosynthetic rates (PR ) of four species of marine single- celled algae were determined by means of 14C-tracer method under the experimental modelling conditions. The effects of environmental factors, such as light, temperature and nutrients, on the biochemical compositions of the algae were studied. The results indicate that the suitable light intensities for the growth of Phaeodactylum tricorntum, Dunaliella spp, Skeletonema costatum and Isochrysis galbana are in the range from 5. 8 X 103 to 15 x 103 lx, showing an increasing trend of photosynthetic rates with the heightened light intensities. The irradiance response of Dunaliella spp. and Isochrysis galbana is significant. The contents of carbohydrate increase, but those of protein decrease, and the contents of lipids change very little. The optimum temperatures for the growth of the four species of algae are 14, 26, 21 and 26t respectively, characterized by the maxima of PR and the contents of carbohydrate, protein and lipid as well as their variations. The apparent activation energies in the photosynthesis process of Phaeodactylum tricornutum, Dunaliella spp., Skeletonema costatum and Isochrysis galbana are 23. 2, 38. 5, 22. 4 and 61. 7 kJ/mol respectively, and the temperature coefficients for the four algae are 1. 74, 1. 74, 1. 38 and 1. 69 respectively. The peaks of PR appeared in some culture media (N/P = 16 ) of Phaeodactylum tricornutum and Skeletonema costatum, and in other media (N/P = 28) of Dunaliella spp. and Isochurysis galbana. The contents and their variations of carbohydrate, protein and lipid of the four species of algae are all maximum when N/P is equal to 16 in culture media.

The study of fluorescence characteristics and biochemical composition of a marine diatom Thalassiosira pseudonana 3H in light and dark cycles—Ⅱ . The effects of light

The effects of light on the fluorescence characteristics and biochemical composition of a marine diatom Tha-lassiosira pseudonana in light and dark cycles were investigated with semi-continuous culture. The results indicate that, with the increase of growing light intensity, DCMU enhanced fluorescence yield (Fd/Chl), enhanced fluorescence ratio (Fd/F) , cellular carbohydrate content. carbohydrate/chlorophyll a and carbohydrate/protein ratio increased , but the fluorescence yield and cellular chlorophyll a content decreased; The protein content declined with the increase of light intensity in the range of 10- 100 μmol/ (m2·s) and increased at higher than 100 μmol/ (m2·s). Sampling time during the day had great effect on the relationships between growing light intensity and cellular chlorophyll a , carbohydrate content , carbohydrate/chlorophyll a and carbohydrate/protein ratio.

The study of fluorescence characteristics and biochemical composition of a marine diatom Thalassiosira pseudonana 3H in light and dark cyclesI. The effects of nutrients

The effects of nutrients on the fluorescence characteristics and biochemical composition of marine diatom Thalassiosira pseudonana 3H in light and dark cycles were investigated with continuous culture. The results show that with the increase of nutrient deficiency, the ratio of enhanced fluorescence to fluorescence (Fd/F), cellular chloropyll-a and protein content of the algae decline, but the fluorescence yield (F/Chl) , DCMU enhanced fluorescence yield (Fd/Chl) , cellular carbohydrate content, carbohydrate/Chl, protein/Chl, carbohydrate/protein increase. The changing amplitude of each parameter is different at different nutrition status, sampling time and different light intensity.

Seasonal variation in the biochemical composition,condition index,and meat yield of the non-indigenous pearl oyster Pinctada imbricata radiata(Leach,1814)from the West of the Aegean Sea,Greece

The average values of the seasonal flesh biochemical composition(%)of the pearl oyster Pinctada imbricata radiata originated form 2 sampling sites,the gulfs of Evoikos(E)and Saronikos(S)in the Western Aegean Sea,showed that is rich in proteins(64.00±1.86-(E),64.67±2.95-(S))with low fat content(10.96±1.04-(E),11.86±1.13-(S))and carbohydrates(13.29±2.48-(E),9.94±4.32(S)).The condition index ranged from 26.16%±5.04 in the autumn in(E),to 44.73%±7.50 in the summer in(S).The meat yield varied from 20.49%±3.20%in the summer in(E)to 30.73%±3.47%in the summer in(S).Both results demonstrate the high nutritional profile of the pearl oyster,supporting its suitability as a potential new Mediterranean seafood source for human consumption.

Evaluation of Nutritional Composition of Two Fonio Ecotypes Grown in Casamance (Sénégal)

In order to better understand the cultural route, biochemical and nutritional composition of two ecotypes of fonio, a study was carried out in village of Tambananing located approximately 7 km from Sédhiou. The objective of studies was to determine nutritional composition of two ecotypes of fonio: the first called momo in short-cycle mandinka (75 - 90 days) and the other called medium-cycle dibong (90 - 110 days). For this, samples of two ecotypes were collected in an experimental field which was split into two equal parts, one sown with the momo ecotype and the other with the dibong ecotype. The nutritional composition (sugars, fats, proteins, minerals, ash, etc.) and the physicochemical properties (pH, humidity, water activity, color, etc.) of fonio’s were determined by appropriate physicochemical methods. The two ecotypes exhibited quite similar physicochemical properties. The levels of biochemical compounds were relatively close with protein contents of 7.05 ± 0.06 mg/100g for the momo ecotype and of 8.02 ± 0.04 mg/100g for the dibong ecotype, in carbohydrates (76.37 ± 1.2 mg/100g for momo and 78.7 ± 1.5 mg/100g for dibong) and in fat (2.92 ± 0.05 mg/100g for momo and 3.14 ± 0.004 mg/100g for dibong). Identical mineral element contents were found except for iron, an element for which the contents were 10.80 ± 0.008 mg/100g for the momo ecotype and 99.59 ± 0.005 mg/100g for the dibong ecotype. Thus, two ecotypes of fonio present a fairly interesting nutritional composition and their consumption deserves to be popularized and could contribute effectively to fight against the problems of malnutrition of certain vulnerable groups.

Accumulation of dysprosium,samarium,terbium,lanthanum,neodymium and ytterbium by Arthrospira platensis and their effects on biomass biochemical composition

The growth of Arthrospira platensis and physiological changes in biomass under the effects of six rare earth elements Dy,Sm,Tb,La,Nd and Yb were evaluated.Elements were tested by three concentrations of 10,20 and 30 mg/L.According to neutron activation analysis data A.platensis’s accumulation capacity toward studied elements changes in the following order of La>Dy>Nd>Sm>Yb>Tb.The results show that Dy and La ions stimulate biomass growth and Yb ions inhibit it,while Sm,Tb and Nd ions do not affect biomass accumulation.The contents of proteins and chlorophyll a are not affected by the presence of rare earth elements in the cultivation medium.Studied elements affect to different extents carbohydrates,phycobilins,β-carotene,lipids and MDA contents in spirulina biomass.Changes in the antioxidant activity under applied metal loads reveal a moderate stress in exposed A.platensis.Cyanobacterium A.platensis can be successfully used for bioremediation of natural water contaminated with REEs as well as REEs recovery from low polluted industrial effluents.

Physico-Chemical and Thermal Characterization of Some Lignocellulosic Fibres: <i>Ananas comosus</i>(AC), <i>Neuropeltis acuminatas</i>(NA) and <i>Rhecktophyllum camerunense</i>(RC)

This paper focuses on the study of the physical, biochemical, structural, and thermal properties of plant fibres of Rhecktophyllum camerunense (RC), Neuropeltis acuminatas (NA) and Ananas comosus (AC) from the equatorial region of Cameroon. The traditional use of these fibres inspired researchers to investigated their properties. This study aims at improving the state of knowledge with a view to diversifying applications. The fibres are extracted by retting. Then, their apparent density was measured following the ASTM D792 standard and their water moisture absorption and moisture content were also evaluated. Their molecular structure was studied by ATR-FTIR spectroscopy. A quantitative analysis of the biochemical composition was performed according to the analytical technique for the pulp and paper industry (TAPPI). A TGA/DSC analysis was also performed. The results reveal that the AC, NA and RC fibres have densities of 1.26 ± 1.06, 0.846 ± 0.13 and 0.757 ± 0.08 g·cm-3 respectively. They are also hydrophilic with a water absorption rate of 188.64 ± 11.94%, 276.16% ± 8.07% and 198.17% ± 20%. They have a moisture content of 12.21%, 10.36% and 9.37%. The studied fibres exhibit functional groups that are related to the presence of hemicellulose, pectin, lignin and cellulose. The cellulose crystallinity index was found to be 67.99%, 46.5% and 59.72% respectively. The fibres under study have the following chemical composition: an extractive content of 3.07%, 14.77% and 8.74%;a pectin content of 4.15%, 7.69% and 3.45%;a hemicellulose content of 4.90%, 15.33% and 7.42%;a cellulose content of 68.11%, 36.08% and 65.15%;a lignin content of 12.01%, 25.15% and 16.2%;and an ash content of 0.27%, 1.53% and 0.47% respectively. The thermal transitions observed on the thermograms correlate with the TAPPI chemical composition. It is observed that these fibres are thermally stable up to temperatures of 200°C, 220°C and 285°C. These results make it possible to envisage uses similar to those of sisal, hemp and flax fibres.

Isolation of a novel strain of Cyanobacterium sp.with good adaptation to extreme alkalinity and high polysaccharide yield

The use of high alkaline medium is a feasible way to provide carbon source and prevent biological contamination for the outdoor cultivation of alkaliphilic microalgae and cyanobacteria.A novel cyanobacterial strain was isolated from the open pond of a marine green alga(Picochlorum sp.SCSIO-45015,Sanya,Hainan)and identified as Cyanobacterium sp.SCSIO-45682.The effects of initial sodium bicarbonate(NaHCO_(3))concentrations on the growth and biochemical composition of Cyanobacterium sp.SCSIO-45682 were investigated.The results demonstrated that Cyanobacterium sp.SCSIO-45682 had good adaptation to 16.8-g/L NaHCO_(3)(the same concentration of NaHCO_(3) used in Zarrouk medium for Spirulina).Moreover,the yields of biomass,polysaccharide,chlorophyll a(chl a),and phycocyanin increased under high NaHCO_(3) concentrations.The maximum final biomass concentration of 2.5 g/L was observed at 8.4-g/L NaHCO_(3),while the highest intracellular total saccharide content of 49.2%of dry weight(DW)and exopolysaccharide(EPS)concentration of 93 mg/L were achieved at the NaHCO_(3) concentration of 16.8 g/L.The crude protein content declined under high NaHCO_(3) concentrations,which provide a possible explanation for the accumulation of polysaccharide.This study shows a good potential of alkaliphilic Cyanobacterium sp.SCSIO-45682 as a polysaccharide feedstock.

Activity of a lipid synthesis inhibitor(spiromesifen) in Culiseta longiareolata(Diptera:Culicidae)

Objective: To evaluate the activity of spiromesifen against the most abundant and investigated mosquito species, Culiseta longiareolata Aitken, 1954(Diptera, Culicidae).Methods: Culiseta longiareolata larvae were collected from untreated areas located at Te′bessa(Northeast Algeria). A commercial formulation of spiromesifen(Oberon?240 SC) was tested at different concentrations ranging between 238 and 1 428 mg/L on newly molted fourth-instar larvae under standard laboratory conditions according to Word Health Organization recommendations. The effects were examined on the mortality, the morphometric measurements, two biomarkers(catalase and malondialdehyde), and the biochemical composition of larvae, respectively.Results: The compound exhibited insecticidal activity. Moreover, it disturbed growth and several morphological aberrations were observed. It also affected body volume,biomarkers and contents of carbohydrates, lipids and proteins. A marked effect on lipids and malondialdehyde was noted, confirming its primary mode of action on lipid synthesis.Conclusions: Spiromesifen appears less potent than other insecticides tested such as the insect growth disruptors.

Study of the Compensatory Growth Following Starvation of Juvenile Golden Pompano Trachinotus ovatus

A starvation trial was conducted to determine compensatory growth of the juvenile golden pompano Trachinotus ovatus which were deprived of food for 1, 2, 5 and 7 days respectively. The results of tests in outdoor cement pools and net pens showed that, in the first 15 days and 30 days, the growth of 1 day and 2 days-deprived groups was probably the same with that of control group, which accorded with fully compensatory description. However, the weight of 5 days and 7 days-deprived fingerlings were lower than that of the control group, which accorded with the description of the partial compensatory growth. As the starvation prolonged, feed conversion efficiency of the starved groups increased and was higher than the control group. Meanwhile, feeding rate also increased, but the fish of 1 day and 2 days-deprived groups was lower than that of the control group, and feeding quantity reduced and was lower than that of the control group. It suggested that the mechanism of compensatory growth was mainly due to improving feed conversion efficiency. Fish biochemical composition was analyzed： the water content and ash of fish sample increased due to starvation, while the lipid and protein decreased. The loss of lipid was greater than that of the protein, and the biochemical composition of fish in each group was restored to the control level by the end of the experiment. It suggested that Trachinotus ovatus may mainly consume lipid during the period of starvation.

Comparative studies on biochemical analysis of some economically important marine gastropods along Gulf of Mannar region,southeast coast of India

Objective:To signify the economic importance of molluscan-gastropod food by estimating its biochemical composition.Methods:Samples were collected from the trawl net bycatch at the fish landing center of Mandapam coast of the Gulf of Mannar region.The total protein,carbohydrate,lipid,ash and moisture contents were estimated from nine gastropods i.e.Phalium glaucum,Tonna dolium,Hemifusus pugilinus,Babylonia spirata,Xancus pyrum,Chicoreus ramosus,Harpa articularis,Ficus ficus and Babylonia zeylanica.Results:The percentages of protein(41.2%),carbohydrate(17.5%)and lipid(6.6%)contents were found highest in Babylonia spirata,followed by other gastropods.The maximum ash content was observed in Chicoreus ramosus(1.21%)and the maximum moisture content was observed in Phalium glaucum(83.71%).Conclusions:The results show that all the nine gastropods contain good sources of protein and other biochemical constituents and can be used for edible purposes to prevent starvation.

Rapid detection of total phenolics,antioxidant activity and ascorbic acid of dried apples by chemometric algorithms

Multivariate approaches like machine learning are commonly used in estimation of biochemical traits from spectral and color characteristics of foodstuffs and agricultural commodities.In present study,windfall apples of Golden Delicious,Oregon Spur and Granny Smith cultivars were dried in open-sun,controlled greenhouse,microwave oven(200W),hybrid system(100W+60℃),convective dryer(70℃)and freeze-dryer(−55℃).Spectral,chromatic and biochemical characteristics of dried apples were determined and assessed through machine learning algorithms.Total phenolic matter,DPPH(2,2-Diphenyl-1-picrylhydrazyl),FRAP(Ferric Reducing Antioxidant Power)and ascorbic acid content were estimated with the use of five different machine learning algorithms(artificial neural networks,k-nearest neighbor,random forest,gaussian processes and support vector regression).The most successful results were achieved in estimation of total phenolic content(R≥0.85).Additionally,Multilayer Perceptron,Support Vector Regression and Gaussian Processes were identified as the best machine learning algorithms in estimation of biochemical compositions of dried apples.

Nutritional evaluation of the moonfish Mene maculata(Bloch&Schneider,1801)from Parangipettai,southeast coast of India

Objective:To assess the nutritions in Mene maculata(Bloch&Schneider,1801)(M.maculata).Methods:Fishes(14-16 cm)were obtained from the landings at Parangipettai for the evaluation of biochemical composition.The present study deals with biochemical composition such as protein,carbohydrate,lipid,amino acids fatty acids,vitamins and minerals which were evaluated in the moonfish.Results:protein was high in the tissue(23.16%),followed by the carbohydrate(1.3%)and lipid(2.62%).Totally 20 essential and nonessential amino acids were present at the rate of 46.72%and 43.91%.In the analysis,the fatty acid profile by gas chromatography revealed the presence of higher amount of saturated fatty acid(palmitic acid 22.17%)than monounsaturated fatty acid(oleic acid 14.51%)and polyunsaturated fatty acid(alpha linolenic acid 16.07%).Vitamins were detected in M.maculata.Among them,vitamin A was found in higher levels(124.5 mg/g),whereas vitamin B6 was noticed as lower levels(0.34 mg/g).In the present study,totally 5 macro minerals and 2 trace minerals were reported.The macro mineral calcium(156.7 mg/g)was found at the highest level and other minerals such as sodium(31.98 mg/g),potassium(21.33 mg/g),copper(1.43 mg/g)and magnesium(0.341 mg/g)were also detected in the moonfish.Conclusions:The results of proximate composition in M.maculata showed that the percentage of The result showed that the moonfish M.maculata tissue is a valuable food recipe for human consumption,due to its high quality protein and well-balanced amino acids.