Publications by authors named "Keyur Raval"

Anthracnose disease, caused by the Colletotrichum gloeosporioides species, affects vegetables, fruits, pulses, and cereals, leading to significant economic losses worldwide. Although many synthetic fungicides are used to control this pathogen, eco-friendly biological alternatives are gaining popularity. This study focuses on isolating and purifying chitinase ( Af Chi)from a marine bacterium and testing its antifungal efficacy against C.

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The development of chitinase tailored for the bioconversion of chitin to chitin oligosaccharides has attracted significant attention due to its potential to alleviate environmental pollution associated with chemical conversion processes. In this present investigation, we purified extracellular chitinase derived from marine Bacillus haynesii to homogeneity and subsequently characterized it. The molecular weight of BhChi was approximately 35 kDa.

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The dwindling supply of the petroleum product and its carbon footprint has initiated search for a sustainable fuel and alternate feed-stocks. One such underexplored feedstock is chitin, a waste derived from sea food processing. The limitation of insolubility and crystallinity inherent in chitin is addressed with the chitin hydrolysates.

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Chitin, an abundant polysaccharide in India, is primary by-product of the seafood industry. Efficiently converting chitin into valuable products is crucial. Chitinase, transforms chitin into chitin oligomers, holds significant industrial potential.

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Reproductive abnormalities in women with a history of childhood diabetes are believed to be partially attributed to hyperglycemia. Prolonged hyperglycemia can negatively affect ovarian function and fertility during reproductive life. To address this in an experimental setting, the present study used streptozotocin-induced hyperglycemic prepubertal mouse model.

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Background: The extended embryo culture using single-step medium gained popularity in clinical in vitro fertilisation (IVF). However, there are concerns about the degradation of unstable medium components and their negative effects on the developing embryos. Further, dry-incubation can increase osmolality, which can in-turn enhance the concentration of constituents of the media and their stability.

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Chitinases convert chitin into chitin oligomers and are also known antifungal agents. Chitin oligomers have numerous industrial applications. However, chitin's crystalline nature requires pretreatment before breakdown into oligomers.

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Melanins are natural pigments, and the presence of indole ring and numerous functional groups makes melanin an ideal choice for many applications such as UV protective agents, skincare, cosmetics etc. A marine Pseudomonas stutzeri produces melanin without the addition of tyrosine. The feedback inhibition was observed by melanin in the culture of a melanin-producing marine bacterium, Pseudomonas stutzeri.

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The metalloid arsenic is one of the most conspicuous groundwater contaminants in the Indian subcontinent and its removal from aqueous medium is the main focus of this study. The study aims at functionalising melanin using iron and copper for the efficient removal of arsenic and rendering water fit for consumption. Melanin obtained from the marine bacteria Pseudomonas stutzeri was functionalised by iron impregnation (Fe-melanin) and copper impregnation (Cu-melanin).

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Heavy metals like mercury, chromium, lead and copper present in groundwater at lower concentrations cause severe health issues and can even be fatal when consumed. The biopigment/biopolymer melanin can be reaped from different sources like bacterium, fungus, and human hair. It has excellent heavy metal ion scavenging property and can be exploited for non-biological applications, substantially including water purification.

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Chitosan obtained by enzymatic deacetylation of chitin using chitin deacetylase (CDA) holds promise primarily due to the possibility to yield chitosan with non-random patterns of acetylation and more environmentally friendly process compared to chemical deacetylation. In the present study, a sustainable bioprocess is reported for over-expression of a bacterial CDA in E. coli pLysS cells.

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Chitosan is a deacetylated form of naturally occurring polymer; chitin. On an industrial scale, the deacetylation of chitin to chitosan is performed using harsh chemicals like sodium hydroxide. This not only adds to the environmental pollution but the product is also random in terms of its deacetylation.

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Heavy metals are one of deadly contaminants in ground water across the globe. Thus, herein, this data set comprises experimental and modelled data on the removal of heavy metals from ground water using melanin synthesized by the marine bacteria . Characterization of biosynthesized melanin and modelling of the kinetic and the thermodynamic study on adsorption of heavy metals such as mercury (Hg(II)), lead (Pb(II)), chromium (Cr(VI)), and copper (Cu(II)) are included in this article.

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The difficulty in removal of heavy metals at concentrations below 10 mg/L has led to the exploration of efficient adsorbents for removal of heavy metals. The adsorption capacity of biosynthesized melanin for Mercury (Hg(II)), Chromium (Cr(VI)), Lead (Pb(II)) and Copper (Cu(II)) was investigated at different operating conditions like pH, time, initial concentration and temperature. The heavy metals adsorption process was well illustrated by the Lagergren's pseudo-second-order kinetic model and the equilibrium data fitted excellently to Langmuir isotherm.

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Chitin, the biopolymer of the N-acetylglucosamine, is the most abundant biopolymer on the planet after cellulose. However owing to its crystalline nature, its deacetylated derivative; chitosan is industrially more potent. This conversion on an enzymatic scale can be made using chitin deacetylase.

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Unlabelled: Laser assisted zona hatching (LAH) is a routinely used therapeutic intervention in assisted reproductive technology for patients with poor prognosis. However, results are not conclusive in demonstrating the benefits of zona hatching in improving the pregnancy rate. Recent observations on LAH induced genetic instability in animal embryos prompted us to look into the effects of laser assisted zona hatching on the human preimplantation embryo quality and metabolic uptake using high resolution nuclear magnetic resonance (NMR) technology.

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Naringinase bioprocess based on Bacillus methylotrophicus was successfully scaled up based on constant oxygen transfer rate (OTR) as the scale-up criterion from 5-L bioreactor to 20-L bioreactor. OTR was measured in 5 and 20-L bioreactor under various operating conditions using dynamic method. The operating conditions, where complete dispersion was observed were identified.

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The effect of major nutrients on growth and azadirachtin-related limonoids (AZRL) production in plant cell culture of Azadirachta indica (neem) was studied with the objective to increase the yield of AZRL, one of the major group of pesticidal compounds found in intact neem trees. We report the novel online monitoring of plant cell respiration activities in a new parallel shake flask measuring device. Results obtained using three standard plant cell culture media showed non-growth-associated production characteristics for AZRL.

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