Production and utilization of the blue-green alga Spirulina in India

An Evaluation of Replacing Fishmeal with Chlorella Sorokiniana in the Diet of Pacific White Shrimp (Litopenaeus Vannamei): Growth, Body Color, and Flesh Quality

This study was conducted to investigate the effects of replacing fishmeal (FM) with Chlorella sorokiniana on growth and flesh quality of Pacific white shrimp, Litopenaeus vannamei. A control diet was formulated to contain 560 g/kg FM, and then chlorella meal was used to replace 0% (C-0), 20% (C-20), 40% (C-40), 60% (C-60), 80% (C-80), and 100% (C-100) of dietary FM, respectively. The six isoproteic and isolipidic diets were fed to shrimp (1.37 ± 0.02 g) for 8 weeks. The results showed that weight gain (WG) and protein retention (PR) of C-20 group were significantly higher than those of C-0 group (P < 0.05), while no significant differences were observed in WG and PR between C-0 and C-40 groups (P > 0.05). When the replaced level of FM by chlorella meal reached 60%, the WG of shrimp decreased and feed conversion ratio (FCR) increased significantly (P < 0.05). The quadratic regression analysis indicated that substituted fishmeal levels with chlorella meal were 20.50% and 28.25%, respectively, to obtain the highest WG and lowest FCR. In C-40 and C-60 groups, the body surface presented higher redness than the control (P < 0.05). No significant differences in the whole body and muscle composition, SOD, T-AOC, GSH-PX activities, MDA contents, total collagen content, steaming loss, texture property, free delicious amino acids contents, PUFAs, and n-3/n-6 PUFAs in flesh were observed among the three groups of C-0, C-20, and C-40 (P > 0.05). Compared to the control group, C-60, C-80, and C-100 groups showed lower flesh hardness, chewiness, shear force, and higher steaming loss and resilience (P < 0.05). There were no significant differences in serum TP, TG, GLU, and ALB contents, boiling loss, freezing loss, total free amino acids, SAFs and MUFAs among all the groups (P >0.05). Conclusively, in a diet containing 560 g/kg FM, chlorella meal could replace 40% dietary FM without negative effects on the growth and flesh quality, while increase the body redness of white shrimp.

The Effect of Colored and White Light on Growth and Phycobiliproteins, Chlorophyll and Carotenoids Content of the Marine Cyanobacteria Phormidium sp. and Cyanothece sp. in Batch Cultures

Two local marine cyanobacteria, Phormidium sp. and Cyanothece sp., were batch-cultured under 18–19.5 °C, at 40 ppt salinity, using white LED light of low (40 μmol photons/m²/s) and high (160 μmol/m²/s) intensity and, additionally, blue, green and red LED light. Yield was highest in high white light in both species (2.15 g dw/L in Phormidium, 1.47 g/L in Cyanothece), followed by green light (1.25 g/L) in Cyanothece and low white and green (1.26–1.33 g/L) in Phormidium. Green light maximized phycocyanin in Phormidium (0.45 mg/mL), while phycoerythrin was enhanced (0.17 mg/mL) by blue light and allophycocyanin by all colors (~0.80 mg/mL). All colors maximized phycocyanin in Cyanothece (~0.32 mg/mL), while phycoerythrin and allophycocyanin peaked under green light (~0.138 and 0.38 mg/mL, respectively). In Phormidium, maximization of chlorophyll-a (9.3 μg/mL) was induced by green light, while total carotenoids and b-carotene (3.05 and 0.89 μg/mL, respectively) by high white light. In Cyanothece, both white light intensities along with green maximized chlorophyll-a (~9 μg/mL) while high white light and green maximized total carotenoids (2.6–3.0 μg/mL). This study strongly indicates that these cyanobacteria can be cultured at the first stage under white light to accumulate sufficient biomass and, subsequently, under colored light for enhancing phycobiliproteins.

Improved spinal cord gray matter morphology induced by Spirulina platensis following spinal cord injury in rat models

Despite intense preclinical research focusing on developing potential strategies of mitigating spinal cord injury (SCI), SCI still results in permanent, debilitating symptoms for which there are currently no effective pharmacological interventions to improve the recovery of the fine ultrastructure of the spinal cord. Spirulina platensis is thought to have potential neuroprotective effects. We have previously demonstrated its protective potential on the lesioned corticospinal tracts and behavioral recovery. In this study, spirulina, known for its neuroprotective properties was used to further explore its protective effects on spinal cord gray matter ultrastructural. Twenty-four Sprague-Dawley rats were used and divided into sham group (laminectomy without SCI), control group (SCI without S. platensis), and S. platensis group (SCI + 180 mg/kg S. platensis). All animals were anesthetized via intramuscular injection. A partial crush injury was induced at the level of T12. The rats were humanely sacrificed for 28 days postinjury for ultrastructural study. There were significant mean differences with respect to pairwise comparisons between the ultrastructural grading score of neuronal perikarya of control and the S. platensis following injury at day 28, which correlates with the functional locomotor recovery at this timepoint in our previous study. The group supplemented with spirulina, thus, revealed a better improvement in the fine ultrastructure of the spinal cord gray matter when compared to the control group thereby suggesting neuroprotective potentials of spirulina in mitigating the effects of spinal cord injury and inducing functional recovery.

Two-Dimensional Thin Layer Chromatography-Bioautography Designed to Separate and Locate Metabolites with Antioxidant Activity Contained on Spirulina platensis

Spirulina platensis contains several biologically active compounds, some of them with antioxidant activity. Nevertheless, not all of these compounds have been identified to date. As a first step to achieving such identification, a methodology to perform two-dimensional thin layer chromatography bioautographies on silica gel thin layer chromatography plates was proposed. Starting with a reference binary system, 5 other binary systems were tested, in which the relative polarity was systematically increased. To further improve the separation behavior, a phase modifier (NH₄OH) was used. The best separation results were obtained with the isopropyl alcohol/ethyl acetate/NH₄OH ternary system. This experimental system allowed four well-resolved spots showing antioxidant activity as well as two additional areas with mixtures containing antioxidant compounds. Although the proposed methodology was designed with a specific application, it would be predictable that its field of use could be considerably greater, making the convenient modifications on the solvent polarity and “masking level” produced by the ammonium derivatives.

High dietary quality of non-toxic cyanobacteria for a benthic grazer and its implications for the control of cyanobacterial biofilms

BACKGROUND

Mass occurrences of cyanobacteria frequently cause detrimental effects to the functioning of aquatic ecosystems. Consequently, attempts haven been made to control cyanobacterial blooms through naturally co-occurring herbivores. Control of cyanobacteria through herbivores often appears to be constrained by their low dietary quality, rather than by the possession of toxins, as also non-toxic cyanobacteria are hardly consumed by many herbivores. It was thus hypothesized that the consumption of non-toxic cyanobacteria may be improved when complemented with other high quality prey. We conducted a laboratory experiment in which we fed the herbivorous freshwater gastropod Lymnaea stagnalis single non-toxic cyanobacterial and unialgal diets or a mixed diet to test if diet-mixing may enable these herbivores to control non-toxic cyanobacterial mass abundances.

RESULTS

The treatments where L. stagnalis were fed non-toxic cyanobacteria and a mixed diet provided a significantly higher shell and soft-body growth rate than the average of all single algal, but not the non-toxic cyanobacterial diets. However, the increase in growth provided by the non-toxic cyanobacteria diets could not be related to typical determinants of dietary quality such as toxicity, nutrient stoichiometry or essential fatty acid content.

CONCLUSIONS

These results strongly contradict previous research which describes non-toxic cyanobacteria as a low quality food resource for freshwater herbivores in general. Our findings thus have strong implications to gastropod-cyanobacteria relationships and suggest that freshwater gastropods may be able to control mass occurrences of benthic non-toxic cyanobacteria, frequently observed in eutrophied water bodies worldwide.

The role of biochemical engineering in the production of biofuels from microalgae

Environmental changes that have occurred due to the use of fossil fuels have driven the search for alternative sources that have a lower environmental impact. First-generation biofuels were derived from crops such as sugar cane, corn and soybean, which contribute to water scarcity and deforestation. Second-generation biofuels originated from lignocellulose agriculture and forest residues, however these needed large areas of land that could be used for food production. Based on technology projections, the third generation of biofuels will be derived from microalgae. Microalgae are considered to be an alternative energy source without the drawbacks of the first- and second-generation biofuels. Depending upon the growing conditions, microalgae can produce biocompounds that are easily converted into biofuels. The biofuels from microalgae are an alternative that can keep the development of human activity in harmony with the environment. This study aimed to present the main biofuels that can be derived from microalgae.

Purification, identification, and characterization of methylcobalamin from Spirulina platensis

The present study reports methylcobalamin in Spirulina platensis using high-performance liquid chromatography (HPLC), thin-layer chromatography (TLC), microbiological assay, chemiluminescence assay, liquid chromatography-mass spectrometry (LC-MS), and tandem mass spectrometry (MS/MS). Extraction of vitamin B12 from S. platensis was carried out without using cyanide. Partial purification was achieved using Amberlite XAD-2 followed by elution with 80% (v/v) methanol. Activated charcoal facilitated removal of impurities in S. platensis extract and in further purification of vitamin B12. The purified fraction was identified to contain methylcobalamin as analyzed by HPLC and TLC. Authenticity of methylcobalamin was further confirmed by LC-MS and MS/MS. Quantitation of methylcobalamin in a test sample of S. platensis biomass was performed using microbiological assay and chemiluminescence assay and was found to be 38.5±2 and 35.7±2 μg/100 g of dry biomass, respectively.

Comparative evaluation of hepatoprotective activity of carotenoids of microalgae

The present study deals with evaluation of the hepatotoprotective activity of carotenoids from two well-known microalgae, Spirulina platensis and Dunaliella salina. Carotenoids were extracted in hexane:isopropyl alcohol (1:1 vol/vol) and fed orally in olive oil to Wistar albino rats at a dose of 100 microg/kg of body weight/day (in terms of carotenoids). The degree of hepatoprotection was measured by estimation of biochemical parameters like serum transaminases [serum glutamate oxaloacetate transaminase (SGOT) and serum glutamate pyruvate transaminase (SGPT)], serum alkaline phosphatase, total albumin, and total protein. The results were compared with those for a control group, a CCl4-induced hepatic damage group, and a group treated with synthetic beta-carotene (all-trans) at the same dose. The protein content of the CCl4-treated group, which received normal diet and a dose of toxin, showed a significant decrease, i.e., 3.92 mg/mL, whereas the protein levels were higher, i.e., 6.96 and 6.32 mg/mL, in the case of the Dunaliella and Spirulina, respectively, carotenoid-treated groups. The CCl4-treated group shown higher activity of transaminases (128.68 units/mL SGPT and 171.52 units/mL SGOT). However, the activity of SGPT was 62.83 units/mL for Dunaliella and 76.83 units/mL for Spirulina, i.e., carotenoids of Dunaliella showed a higher degree of protection. For serum alkaline phosphatase, the standard beta-carotene value was 81.52 units/mL, compared with 84.46 units/mL for the CCl4-treated group; however, natural algal carotenoids yielded 38.45 units/mL (D. salina) and 44.73 units/mL (Spirulina). The total albumin value diminished with CCl4 treatment (2.46 mg/mL); the effect was highest for Dunaliella, followed by the Spirulina carotenoid-treated group. The results clearly indicate that carotenoids from Dunaliella possess better hepatoprotection compared with those from Spirulina. High-performance liquid chromatography of the carotenoids indicated that Spirulina contains only beta-carotene and Dunaliella contains other carotenoids and xanthophyll. The increase in protection with Dunaliella indicates that mixed carotenoids exhibit better biological activity than beta-carotene alone. The results of this study indicate that carotenoids obtained from an algal source have a higher antihepatotoxic effect, compared with synthetic beta-carotene and with beta-carotene alone from a natural source.

Cadmium biosorption by cells of Spirulina platensis TISTR 8217 immobilized in alginate and silica gel

The biosorption of cadmium by immobilized Spirulina platensis on alginate gel and silica gel was studied. The maximum biosorption capacities for alginate immobilized cells and silica immobilized cells were 70.92 and 36.63 mg Cd/g biomass, respectively. Temperature did not have an influence on metal sorption, whereas an initial pH solution did. Sorption occurred in a wide pH range (pH 3-8). The highest adsorption of alginate immobilized cells was at pH 6, while silica immobilized cell adsorption was not affected at pH between 4 and 7. The immobilized cells were reused in consecutive adsorption-desorption. The results showed that immobilized cells could be repeatedly used in the sorption process up to five times.

Growth performance of two Indian major carps, catla (Catla catla) and rohu (Labeo rohita) fed diets containing different levels of Spirulina platensis

The influence of Spirulina platensis meal on the growth and carcass composition of two Indian major carps, catla, Catla catla and rohu, Labeo rohita was investigated in a 90-day culture trial. Four experimental diets were used and Spirulina replaced fish meal protein from the standard diet at 25%, 50%, 75% and 100% levels. There was no significant difference in the final weight attained by catla at all levels of Spirulina incorporation as compared to the fish-meal-based control diet. However, the replacement of fish meal by more than 25% Spirulina resulted in significantly superior growth of rohu. The specific growth rate and protein efficiency ratio recorded in rohu improved with higher levels of Spirulina inclusion, while in catla they did not differ significantly from the control treatment. In both the species, the digestibility of dry matter, protein and fat was found to improve marginally with increasing levels of Spirulina incorporation. The carcass composition showed an inverse relationship between protein and fat deposition. In general, fish fed with Spirulina diets had a significantly higher percentage of fat. The study demonstrated the usefulness of Spirulina for partial or complete replacement of fish meal in the diets of catla and rohu.

Subchronic toxicity study in mice fed Spirulina maxima

The purpose of this study was to evaluate the toxicity of Spirulina maxima, a blue-green alga used as food supplement and food coloring, after 13 weeks of treatment. Groups of ten mice of each sex were given S. maxima in the diet at concentrations of 0 (control), 10, 20 or 30% (w/w) for 13 weeks. The alga ingestion had no effect on behavior, food and water intake, growth or survival. Terminal values in hematology and clinical chemistry did not reveal differences between treated and control groups. However, male and female mice showed significant changes in serum cholesterol levels at 20 and 30% algal concentrations, but a toxic effect of S. maxima was excluded. Post-mortem examination revealed no differences in gross or microscopic findings. Our results show that S. maxima up to high feeding levels did not produce adverse effects in mice after subchronic treatment.

Effect of Spirulina maxima consumption on reproduction and peri- and postnatal development in rats

Spirulina maxima, an edible micro-organism useful in human nutrition, was examined for its effect on general reproductive performance and for peri- and postnatal toxicity in rats at levels of 0, 10, 20 and 30% (w/w) incorporated into the diet. There was no reduction in body weight gain in males or females and no deaths or clinical signs of toxicity. Treatment was not associated with any adverse effect on any measure of reproductive performance, including male and female fertility and duration of gestation. There was no increase in the number of abnormal pups at caesarean section or at birth. S. maxima consumption did not result in adverse effects on developmental markers of the pups.

Compositional and toxicological evaluation of the diazotrophic cyanobacterium, Cyanothece sp. strain ATCC 51142

Compositional analyses of Cyanothece sp. strain ATCC 51142 showed high protein (50-60%) and low fat (0.4-1%) content, and the ability to synthesize vitamin B12. The amino acid profile indicated that Cyanothece sp. was a balanced protein source. Fatty acids of the 18:3n-3 type were also present. Mineral analyses indicated that the cellular biomass may be a good source of Fe, Zn and Na. Caloric content was 4.5 to 5.1 kcal g dry weight-1 and the carbon content was approximately 40% on a dry weight basis. Nitrogen content was 8 to 9% on a dry weight basis and total nucleic acids were 1.3% on a dry weight basis. Short-term feeding studies in rats followed by histopathology found no toxicity or dietary incompatibility problems. The level of uric acid and allantoin in urine and tissues was low, suggesting no excess of nucleic acids, as sometimes reported in the past for a cyanobacteria-containing diet. The current work discusses the potential implications of these results for human nutrition applications.

Replacement value of blue-green alga (Spirulina platensis) for fishmeal and a vitamin-mineral premix for broiler chicks

1. The effect of sun-dried Spirulina platensis in poultry diets was studied in a 12-week feeding trial by replacing either fishmeal (FM) or groundnut cake (GC) in a commercial diet with algae at isonitrogenous concentrations of 140 g/kg and 170 g/kg respectively. Additional vitamins/minerals were omitted from the algal diets because Spirulina is rich in them. 2. Efficiency of food utilisation, protein efficiency ratio and dressing percentage indicated that substitution of FM or GC by alga did not affect the performance of broilers. 3. None of the diets affected the weights, compositions and histopathology of the various organs of the chicks. 4. Meat quality remained unchanged except for a more intense colour in the case of birds fed on the alga-containing diets.

Effect of supplementation of blue green alga (Spirulina) on outcome of pregnancy in rats

To study the supplementary effect of Spirulina, pregnant rats were fed 5 different kinds of diets (casein, Spirulina, wheat gluten, Spirulina + wheat gluten, Spirulina-without additional vitamins and minerals), each providing 22% protein during the period of pregnancy. The outcome of pregnancy was assessed from litter and dams' weight and litter size. Maternal weight gain was found to be maximum with Spirulina + wheat gluten and least with the wheat gluten diet. Rats receiving Spirulina containing diets produced significantly (p < 0.05) higher litter size than those receiving casein and wheat gluten. In spite of having higher litter size, Spirulina containing diet groups produced pups with birth weights comparable to those of casein. Spirulina appears to be a good dietary supplement during pregnancy.