Biological and physiological responses of marine crabs to ocean acidification: A review.

Marine crabs play an integral role in the food chain and scavenge the debris in the ecosystem. Gradual increases in global atmospheric carbon dioxide cause ocean acidification (OA) and global warming that leads to severe consequences for marine organisms including crabs. Also, OA combined with other stressors like temperature, hypoxia, and heavy metals causes more severe adverse effects in marine crabs. The present review was made holistic discussion of information from 111 articles, of which 37 peer-reviewed original research papers reported on the effect of OA experiments and its combination with other stressors like heavy metals, temperature, and hypoxia on growth, survival, molting, chitin quality, food indices, tissue biochemical constituents, hemocytes population, and biomarker enzymes of marine crabs. Nevertheless, the available reports are still in the infancy of marine crabs, hence, this review depicts the possible gaps and future research needs on the impact of OA on marine crabs.

Toxic effects of organophosphate pesticide monocrotophos in aquatic organisms: A review of challenges, regulations and future perspectives.

In recent times, usage of pesticide, herbicides and synthetic fertilizers in farming lands has made the environment worse. The pesticide residues and toxic byproducts from agricultural lands were found to contaminate the aquatic ecosystem. The misuse of synthetic pesticide not only affects the environment, but also affects the health status of aquatic organisms. The organophosphate pesticide pollutants are emerging contaminants, which threatens the terrestrial and aquatic ecosystem. Monocrotophos (MCP) is an organophosphate insecticide, utilized on crops including rice, maize, sugarcane, cotton, soybeans, groundnuts and vegetables. MCP is hydrophilic in nature and their solubilizing properties reduce the soil sorption which leads to groundwater contamination. The half-life period of MCP is 17-96 and the half-life period of technical grade MCP is 2500 days if held stable at 38 °C in a container. MCP causes mild to severe confusion, anxiety, hyper-salivation, convulsion and respiratory distress in mammals as well as aquatic animals. The MCP induced toxicity including survival rate, behavioural changes, reproductive toxicity and genotoxicity in different aquatic species have been discussed in this review. Furthermore, the ultimate aim of this review is to highlight the international regulations, future perspectives and challenges involved in using the MCP.

Chitin, chitosan and chitooligosaccharides as potential growth promoters and immunostimulants in aquaculture: A comprehensive review.

There is a stable growth in aquaculture production to avoid seafood scarcity. The usage of eco-friendly feed additives is not only associated with aquatic animal health but also reduces the risk of deleterious effects to the environment and consumers. Aquaculture researchers are seeking dietary solutions to improve the growth performance and yield of target organisms. A wide range of naturally derived compounds such as probiotics, prebiotics, synbiotics, complex carbohydrates, nutritional factors, herbs, hormones, vitamins, and cytokines was utilized as immunostimulants in aquaculture. The use of polysaccharides derived from natural resources, such as alginate, agar, laminarin, carrageenan, fucoidan, chitin, and chitosan, as supplementary feed in aquaculture species has been reported. Polysaccharides are prebiotic substances which are enhancing the immunity, disease resistance and growth of aquatic animals. Further, chitin (CT), chitosan (CTS) and chitooligosaccharides (COS) were recognized for their biodegradable properties and unique biological functions. The dietary effects of CT, CTS and COS at different inclusion levels on growth performance, immune response and gut microbiota in aquaculture species has been reviewed. The safety regulations, challenges and future outlooks of CT, CTS and COS in aquatic animals have been discussed in this review.

Black soldier fly (Hermetia illucens) larvae as potential feedstock for the biodiesel production: Recent advances and challenges.

Black soldier fly larvae (BSFL) Hermetia illucens is fastest growing and most promising insect species especially recommended to bring high-fat content as 5th generation bioenergy. The fat content can be fully optimized during the life-cycle of the BSFL through various organic dietary supplements and environmental conditions. Enriched fat can be obtained during the larval stages of the BSF. The presence of high saturated and unsaturated fatty acids in their body helps to produce 70 % of extractable oil which can be converted into biodiesel through transesterification. The first-generation biodiesel process mainly depends on catalytic transesterification, however, BSFL had 94 % of biodiesel production through non-catalytic transesterification. This increases the sustainability of producing biodiesel with less energy input in the process line. Other carbon emitting factors involved in the rearing of BSFL are less than the other biodiesel feedstocks including microalgae, cooking oil, and non-edible oil. Therefore, this review is focused on evaluating the optimum dietary source to produce fatty acid rich larvae and larval growth to accumulate C16-18 fatty acids in larger amounts from agro food waste. The process of optimization and biorefining of lipids using novel techniques have been discussed herein. The sustainability impact was evaluated from the cultivation to biodiesel conversion with greenhouse gas emissions scores in the entire life-cycle of process flow. The state-of-the-art in connecting circular bioeconomy loop in the search for bioenergy was meticulously covered.

Green and eco-friendly approaches for the extraction of chitin and chitosan: A review.

Chitin is one of the most diverse and naturally occurring biopolymers, and it is mainly present in crustaceans, insects, and fungi. Chitosan is derived from chitin by deacetylation process. It is important to note that the conventional chemical method of extracting chitin includes disadvantages and it poses various environmental issues. Recently, the green extraction techniques have perceived substantial development in the field of polymer chemistry. A variety of methods have been successfully developed using green extraction techniques for extracting chitin and chitosan from various resources. It includes the use of ionic liquids (ILs), deep eutectic solvents (DES), microbial fermentation, enzyme-assisted extraction (EAE), microwave-assisted extraction (MAE), ultrasonic-assisted extraction (UAE), subcritical water extraction (SWE), and electrochemical extraction (ECE). In this review, the extraction of chitin and chitosan using greener approaches were summarized. In addition, challenges, opportunities and future perspectives of green extraction methods have also been narrated.

Distribution, toxicity, interactive effects, and detection of ochratoxin and deoxynivalenol in food: A review.

Mycotoxins are secondary metabolites of fungi that cause severe damage to agricultural products and food in the food supply chain. These detrimental pollutants have been directly linked with poor socioeconomic patterns and human health issues. Among the natural micropollutants, ochratoxin A (OTA) and deoxynivalenol (DON) are widely distributed in food materials. The primary occurrence of these mycotoxins is reported in almost all cereal grains and fresh agro-products. Both mycotoxins have shown harmful effects, such as nephrotoxic, hepatotoxic, and genotoxic effects, in humans due to their complex structural formation during the degradation/acetylation reaction. In addition, improper preharvest, harvest, and postharvest handling tend to lead to the formation of OTA and DON in various food commodities, which allows different harmful fungicides in practice. Therefore, this review provides more insight into the distribution and toxicity of OTA/DON in the food matrix and human health. Furthermore, the interactive effects of OTA/DON with co-contaminated organic and inorganic compounds are discussed. Finally, international regulation and mitigation strategies for detoxication are critically evaluated to meet food safety and good agriculture practices.

Dieckol: a brown algal phlorotannin with biological potential.

Dieckol [C36H22O18], is a naturally occurring phlorotannin found in some brown algal species. Dieckol is gaining more attention in the scientific community for its potential biological activities. It has been exhibited a broad spectrum of therapeutic functions including anti-bacterial, anti-cancer, anti-oxidant, anti-aging, anti-diabetic, neuroprotective, and other medicinal applications. Distinct emphasis has been given to extraction, purification, and biomedical applications of dieckol. This critical review comprises of in vitro, in vivo, and in silico biological properties of dieckol. An attempt has been made to evaluate the effectiveness, therapeutical application, and mechanism of dieckol against various diseases. The pharmacological significance, current status and the dosage of multifunctional dieckol and its mechanisms have been discussed in this review. Dieckol plays an important role in apoptosis induction via inhibiting the PI3K, AKT, mTOR and FAK signaling molecules. Dieckol remarkably inhibited the lipid accumulation in high fat diet induced animal models. Dieckol, a multifaceted compound will be beneficial in attenuating the action of various diseases and it could be a potential pharmaceutical and nutraceutical compound. Therefore, the combined effects of dieckol with existing drugs and natural compounds will be studied in future to optimize its benefits. Besides limited information on the toxicological action and dosage administration of dieckol on the human was reported to date. Overall, dieckol is a prospective health-promoting compound for the development of a novel drug against numerous diseases.

Hazardous impact of diclofenac on mammalian system: Mitigation strategy through green remediation approach.

Diclofenac is an anti-inflammatory drug used as an analgesic. It is often detected in various environmental sources around the world and is considered as one of the emerging contaminants (ECs). This paper reviews the distribution of diclofenac at high concentrations in diverse environments and its adverse ecological impact. Recent studies observed strong evidence of the hazardous effect of diclofenac on mammals, including humans. Diclofenac could cause gastrointestinal complications, neurotoxicity, cardiotoxicity, hepatotoxicity, nephrotoxicity, hematotoxicity, genotoxicity, teratogenicity, bone fractures, and skin allergy in mammals even at a low concentration. Collectively, this comprehensive review relates the mode of toxicity, level of exposure, and route of administration as a unique approach for addressing the destructive consequence of diclofenac in mammalian systems. Finally, the mitigation strategy to eradicate the diclofenac toxicity through green remediation is critically discussed. This review will undoubtedly shed light on the toxic effects of pseudo-persistent diclofenac on mammals as well as frame stringent guidelines against its common usage.

Recent insights into the extraction, characterization, and bioactivities of chitin and chitosan from insects.

BACKGROUND: Insects are a living resource used for human nutrition, medicine, and industry. Several potential sources of proteins, peptides, and biopolymers, such as silk, chitin, and chitosan are utilized in industry and for biotechnology applications. Chitosan is an amino-polysaccharide derivative of chitin that consists of linear amino polysaccharides with d-glucosamine and N-acetyl-d-glucosamine units. Currently, the chief commercial sources of chitin and chitosan are crustacean shells that accumulate as a major waste product from the marine food industry. Existing chitin resources have some natural challenges, including insufficient supplies, seasonal availability, and environmental pollution. As an alternative, insects could be utilized as unconventional but feasible sources of chitin and chitosan. SCOPE AND APPROACH: This review focuses on the recent sources of insect chitin and chitosan, particularly from the Lepidoptera, Coleoptera, Orthoptera, Hymenoptera, Diptera, Hemiptera, Dictyoptera, and Odonata orders. In addition, the extraction methods and physicochemical characteristics are discussed. Insect chitin and chitosan have numerous biological activities and could be used for food, biomedical, and industrial applications. KEY FINDINGS AND CONCLUSIONS: Recently, the invasive and harmful effects of insect species causing severe damage in agricultural crops has led to great economic losses globally. These dangerous species serve as potential sources of chitin and are underutilized worldwide. The conclusion of the present study provides better insight into the conversion of insect waste-derived chitin into value-added products as an alternative chitin source to address food security related challenges.

Purification, characterization and biological functions of metalloprotein isolated from haemolymph of mud crab Scylla serrata (Forskal, 1775).

In recent years, an enormous number of naturally occurring biological macromolecules has been reported worldwide due to its antibacterial and anticancerous potential. Among them, in this study, the copper containing respiratory protein namely haemocyanin (HC) was isolated from the haemolymph of mud crab Scylla serrata. The isolated metalloprotein HC was purified using Sepharose column by gel filtration chromatography. The purified HC was separated by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and molecular weight of the protein was identified as 95 kDa. Fourier transform infrared spectrophotometer (FT-IR) and nuclear magnetic resonance (1H NMR) spectral data revealed the presence of amino acid constituents. Liquid chromatography tandem mass spectrometry (LC-MS/MS) analysis based mass ion search exposed that the purified protein was HC. HC exhibited an in vitro bacteriostatic effects against the bacterial pathogens and also elevated ROS levels in the treated samples. The half maximal (50%) inhibitory concentration (IC50) of HC was found to be 80 µg/mL against lung cancer cells (A549). Our study collectively addressed the potential antibacterial and anti-cancerous activity of HC. The results obtained from this study suggest that HC can be used for therapeutical application in the near future.

Trends in the extraction, purification, characterisation and biological activities of polysaccharides from tropical and sub-tropical fruits - A comprehensive review.

Tropical and sub-tropical fruits are tremendous sources of polysaccharides (PSs), which are of great interest in the human welfare system as natural medicines, food and cosmetics. This review paper aims to highlight the recent trends in extraction (conventional and non-conventional), purification and analytic techniques of fruit polysaccharides (FPSs). The chemical structure and biological activities, such as immunomodulatory, anti-cancer, anti-oxidant, anti-inflammatory, anti-viral, anti-coagulant and anti-diabetic effects, of PSs extracted from 53 various fruits were compared and discussed. With this wide coverage, a total of 172 scientific articles were reviewed and discussed. This comprehensive survey from previous studies suggests that the FPSs are non-toxic and highly biocompatible. In addition, this review highlights that FPSs might be excellent functional foods as well as effective therapeutic drugs. Finally, the future research advances of FPSs are also described. The content of this review will promote human wellness-based food product development in the future.

Multi-elemental concentration in different body parts of Sepiella inermis by inductively coupled plasma mass spectrometry.

The present study examined the accumulation of metal on Sepiella inermis from the Mudasalodai Landing Center, from southeast coastal region of India. Inductively coupled plasma mass spectrometry (ICP-MS) was used to determine metals including aluminium, boron, cadmium, cobalt, chromium, copper, iron, manganese, magnesium, nickel, lead and zinc. The results showed that metal concentration in S. inermis detected in the head, arm, mantle, eye, ink, liver and nidamental gland with higher concentration of magnesium up to 992.78 mg/kg, and tentacle showed maximum concentration of aluminium 306.72 mg/kg. Further, copper found in low concentration ranges from 0.04 to 0.55 mg/kg in different parts of S. inermis. Heavy metal like cadmium detected high in tentacle with 0.24 mg/kg, and the manganese present in eye was 0.55 mg/kg. However, no accumulation of nickel was found in the tentacle part.

Distribution and risk assessment of trace metals in multifarious matrices of Vembanad Lake system, Peninsular India.

Trace metal contamination in aquatic ecosystems is of significant concern in countries like India having a recent industrial history. The present study mainly focuses on the spatial and temporal distribution, occurrence and toxicity of five trace metals (Hg, Cd, Zn, Cu and Pb) in water and sediment matrix of Vembanad Lake system (VLS), India. Mercury analysis was done by using Cold Vapor Atomic Fluorescence Spectrometer, and the other metals were analysed using Volta metric-Trace metal analyser. The spatial distribution of trace metals in the study area showed the following trends, Zn > Pb > Cu > Cd > Hg, Zn > Pb > Cu > Hg > Cd for surface water and bottom water respectively. Health risk assessment on human population associated with trace metals was also calculated to predict their health impacts on human through non-dietary exposure. The trace metals contamination in water and sediments of VLS are potential to cause cancer on human population associated with the system. Ecological risk indices showed that the northern portion of VLS is more contaminated with trace metal than the other part of the system.

Application of marine-derived polysaccharides as immunostimulants in aquaculture: A review of current knowledge and further perspectives.

The use of antibiotics in the feeds of cultivable aquatic animals has been generally practised to reduce infectious diseases as well as to improve the survival and growth. In recent years, many countries ban to aquatic animals due to the use of large amount of antibiotics and chemotherapies, thus alternative novel strategies are need to promote the growth of aquatic animals and control the pathogens. Dietary supplementation of marine-derived polysaccharides (MDPs) is one of the potential substitutes for antibiotics in aquatic animal feeds. Recently, the use of dietary MDPs in the aquaculture animals has been focused with much interest. In aquaculture, MDPs are used as prebiotic substance which is mostly accepted as a nutritional component for improving the growth performance and health conditions. Hence, present review is a comprehensive and an updated collection of available research reports on different MDPs (alginate, fucoidan, carrageenan, laminarin, ulvan, galactan, agar, chitin and chitosan), route of administration, dosage and applications for improving aqua feeds with emphasis on its effects on growth, biochemical indices, immune response, gut microbiota and disease resistance of aquaculture animals. This review describes the sustainability of global aquaculture production by providing a best alternative to harmful antibiotics, thereby meeting the emerging consumer demand for antibiotic-free aquatic food products.

Extraction and characterization of chitin from sea snail Conus inscriptus (Reeve, 1843).

The chitin was extracted from C. inscriptus and the structure was elucidated. The yield of the C. inscriptus shell chitin was 21.65% on dry weight basis. The ash and moisture content of the chitin was 1.2 and 6.50%. The result of the molecular analysis of the chitin revealed low molecular weight (25 kDa). The crystalline structure (XRD), functional group (FT-IR), elemental analysis (EDAX), surface morphology (SEM) and thermal stability (TG/DTA) results confirmed conus chitin was in α-crystalline form. The crystalline index value (CrI) of the conus chitin was 82.13%. The FT-IR analysis of the conus chitin displayed two bands at around 1730 and 1628 cm-1. SEM investigation of the commercial chitin and C. inscriptus chitin exposed that it was composed of nanopore and nanofibre structures. Further, the thermal stability of the conus chitin was close to the thermal stability of the commercial chitin. The results show that processing of C. inscriptus shell can lead to a high quality chitin, useful for a broad range of applications.

Chemical structure and biological properties of a polysaccharide isolated from Pleurotus sajor-caju.

Herein, a polysaccharide obtained from Pleurotus sajor-caju was fractionated via anion-exchange column chromatography and purified using gel permeation column chromatography. The chemical characterization of the polysaccharide indicated that it contained 90.16% total carbohydrate, 0% protein, 12.7% ash and 5.2% moisture; on the other hand, the carbon, hydrogen and nitrogen contents were found to be 31.53, 4.28 and 3.01%, respectively. The polysaccharide has the molecular weight of 79 kDa; the chemical structure of the polysaccharide is →6)α-d-Glciv(1→6)α-d-Glciii(1→6)ß-d-Glcii(1→6)α-d-Glci(1→units. The polysaccharide exhibited the DPPH radical scavenging activity of 21.67-68.35% at 10-160 µg ml-1, ABTS radical scavenging activity of 16.01-70.09% at 25-125 µg ml-1, superoxide radical scavenging activity of 24.31-73.64% at 50-250 µg ml-1, hydroxyl radical scavenging activity of 16.64-63.51% at 25-125 µg ml-1 and reducing power of 0.366-1.678% at 10-120 µg ml; further evaluation of the polysaccharide revealed its anticancer activity of 18.61-63.21% at 100-500 µg ml-1 concentration against the AGS human gastric carcinoma cell line. The active principle of the polysaccharide may be used in the food and pharmacological industry in the future.

Seroprevalence of certain bacterial and viral infections among the Irula tribal population of Marakkanam, Tamil Nadu state, India.

AIM: Seroprevalence study in Irula tribe of Marakkanam, Tamil Nadu State was carried out for certain bacterial (typhoid, syphilis and leptospirosis) and viral infection (hanta, hepatitis B and human immunodeficiency virus (HIV)). RESULT: Highest seroprevalence was observed for leptospirosis (61.1%) followed by, hepatitis B virus surface antigen (11.11%), syphilis (9.72%), typhoid (8.33%), hantavirus (6.9%) and HIV (2.77%). OBSERVATION: The seroprevalence of leptospirosis and hantavirus may be attributed to their professional exposure to rodent that they catch in the open field and the syphilis, hepatitis B and HIV prevalence may be related to their sexual behavior and social customs.