Amino Acid Composition of Thirty Food Fishes of the Ganga Riverine Environment for Addressing Amino Acid Requirement through Fish Supplementation.

Amino acids are significant biomolecules that govern the major metabolic processes and act as precursors for macromolecules such as proteins that are crucial to life. Fish is an integral component of human nutrition and a dietary source of high-quality animal proteins and amino acids. In this context, the crude protein and amino acid compositions of food fish from different landing stations of the Ganga river have been determined. The Kjeldahl method was utilized to determine the crude protein content and the amino acids were analyzed using high-performance liquid chromatography (HPLC); data on 30 food fish were assessed. The study showed that among the fish studied, Eleotris fusca, Macrobrachium malcomsonii, and Mystus cavasius were rich in most of the amino acids important for human nutrition, such as glycine, glutamic acid, cysteine, threonine, phenylalanine, methionine, lysine, leucine, isoleucine, histidine, and valine. Further, it was observed that the daily consumption of these fish (approximately 50 g) can fulfil the daily requirement of these individual amino acids for an adult human with a body weight of 60 kg. Therefore, the amino acid composition analyzed in the present study could be utilized for recommendation by clinicians according to the requirement for specific amino acids, and fish can be prescribed as a natural supplement against the amino acid requirement.

Bioaccumulation of arsenic in fish (Labeo rohita) in presence of periphyton: ameliorative effect on oxidative stress, physiological condition, immune response and risk assessment.

The present study explores the use of periphyton to ameliorate toxic properties of arsenic (As) to Labeo rohita and also assesses the human food safety aspects. Fish were introduced to arsenite [As(III)] contaminated water (0.3 and 3 mg/L) along with periphyton. Biochemical, physiological and immunological parameters, including gene expression, were assessed after 30 days of exposure. Periphyton incorporation significantly improved (p < 0.05) the adverse effects of As on respiration, NH3 excretion and brain AChE activity by reducing oxidative stress and As bioaccumulation. The presence of periphyton in As(III) exposed fish (3 mg/L) increased the immune response (Immunoglobulin M and Complement C3) in the serum and the regulation of the respective immune genes in the anterior kidney was found to be similar to the control. A speciation study using LC-ICP-MS confirmed the high accumulation of As by periphyton (5.0-31.9 µg/g) as arsenate [As (V)], resulting in a lower amount of As in fish muscle. The calculated human health risk indices, Target Hazard Quotient (THQ) and Target Cancer risk (TCR) indicate that fish grown in periphyton-treated water may lower the human health risks associated with As. The study signifies the importance of periphyton-based aquaculture systems in As contaminated regions for safe fish production with enhanced yield.

Sustainable biodiesel production from microalgae Graesiella emersonii through valorization of garden wastes-based vermicompost.

Biodiesel production from microalgae has gained significant interest recently due to the growing energy demand and non-renewable nature of petroleum. However, high cost of production and environmental health related issues like excess use of inorganic fertilizers, eutrophication are the major constraints in commercial-scale biodiesel production. Besides this, solid wastes (garden-based) management is also a global concern. In the present study, to overcome these limitations vermicompost extract was tested as nutrient source to enhance growth performance and lipid production from a freshwater microalga (Graesiella emersonii MN877773). Garden wastes were first converted into vermicompost manure and its extract (aerobic and anaerobically digested) was prepared. The efficacy of the extract was then tested in combination with BG11 medium. The mixotrophic cultivation of microalgae in anaerobically digested vermicompost extract at 50:50 combination with BG11 medium enhanced the cell biomass (0.64 g d. wt. L-1) and lipid productivity (3.18 mg L-1 day-1) of microalgae by two times. Moreover, the combination also improved the saturated (methyl palmitate) and monounsaturated fatty acids (oleic acid) content in the test algae. The quality of biodiesel also complies with all the properties of biodiesel standard provided by India, the USA, and Europe except the cold filter plugging property. The combination was also found to improve the cell biomass (0.041 g L-1) as compared to BG11 medium in mass-scale cultivation. Hence, the study proved that G. emersonii grown in media supplemented with garden waste-based vermicompost extract had significant potential for mass-scale biodiesel and bioproduct production.

Arsenic Bioaccumulation and Identification of Low-Arsenic-Accumulating Food Fishes for Aquaculture in Arsenic-Contaminated Ponds and Associated Aquatic Ecosystems.

Arsenic-contaminated food including farmed fish is one of the main routes of human exposure. Fish farmed in contaminated environment accumulates arsenic in different tissues with great variability. Thus, it is utmost important to quantify the risk associated with different farmed fish species in arsenic-contaminated aquaculture systems. In the present study, arsenic content was measured in twelve fish species (Labeo rohita, L. catla, Cirrhinus mrigala, Oreochromis niloticus, O. mossambicus, Liza tade, Puntius javanicus, L. calbasu, Glossogobius giuris, Macrobrachium rosenbergii, Ctenopharyngodon idella, and Bellamya bengalensis (gastropod)) collected from arsenic-contaminated aquaculture systems. Among the studied finfishes, C. idella was found to accumulate the lowest amount of arsenic (< 0.05 ± 0.00 mg kg-1) whereas the highest accumulation was noticed in O. mossambicus (1.0 ± 0.18 mg kg-1). However, the estimated carcinogenic and non-carcinogenic risks of human were found to be low for all the studied fishes. The calculated target hazard quotient (THQ) value for adults ranged from 0.01 to 0.08 whereas for children it ranged from 0.05 to 0.27 for low-arsenic-accumulating fishes (arsenic conc. < 0.5 mg kg-1). Based on these findings, C. mrigala, C. idella, and M. rosenbergii could be recommended as the candidate species for aquaculture in the arsenic-contaminated areas as farming of the low-arsenic-accumulating food fishes would also lower the risk of human exposure through food chain.