Characterization of L-asparaginase from Bacillus sp. isolated from an intertidal marine alga (Sargassum sp.)

Marine microbial L-asparaginase: Biochemistry, molecular approaches and applications in tumor therapy and in food industry

The marine environment is a rich source of biological and chemical diversity. It covers more than 70% of the Earth's surface and features a wide diversity of habitats, often displaying extreme conditions, where marine organisms thrive, offering a vast pool for microorganisms and enzymes. Given the dissimilarity between marine and terrestrial habitats, enzymes and microorganisms, either novel or with different and appealing features as compared to terrestrial counterparts, may be identified and isolated. L-asparaginase (E.C. 3.5.1.1), is among the relevant enzymes that can be obtained from marine sources. This amidohydrolase acts on L-asparagine and produce L-aspartate and ammonia, accordingly it has an acknowledged chemotherapeutic application, namely in acute lymphoblastic leukemia. Moreover, L-asparaginase is also of interest in the food industry as it prevents acrylamide formation. Terrestrial organisms have been largely tapped for L-asparaginases, but most failed to comply with criteria for practical applications, whereas marine sources have only been marginally screened. This work provides an overview on the relevant features of this enzyme and the framework for its application, with a clear emphasis on the use of L-asparaginase from marine sources. The review envisages to highlight the unique properties of marine L-asparaginases that could make them good candidates for medical applications and industries, especially in food safety.

Solid-State Fermentation vs Submerged Fermentation for the Production of l-Asparaginase

l-Asparaginase, an enzyme that catalyzes l-asparagine into aspartic acid and ammonia, has relevant applications in the pharmaceutical and food industry. So, this enzyme is used in the treatment of acute lymphoblastic leukemia, a malignant disorder in children. This enzyme is also able to reduce the amount of acrylamide found in carbohydrate-rich fried and baked foods which is carcinogenic to humans. The concentration of acrylamide in food can be reduced by deamination of asparagine using l-Asparaginase. l-Asparaginase is present in plants, animals, and microbes. Various microorganisms such as bacteria, yeast, and fungi are generally used for the production of l-Asparaginase as it is difficult to obtain the same from plants and animals. l-Asparaginase from bacteria causes anaphylaxis and other abnormal sensitive reactions. To overcome this, eukaryotic organisms such as fungi can be used for the production of l-Asparaginase. l-Asparaginase can be produced either by solid-state fermentation (SSF) or by submerged fermentation (SmF). SSF is preferred over SmF as it is cost effective, eco-friendly and it delivers high yield of enzyme. SSF process utilizes agricultural and industrial wastes as solid substrate. The contamination level is substantially reduced in SSF through low moisture content. Current chapter will discuss in detail the chemistry and applications of l-Asparaginase enzyme and various methods available for the production of the enzyme, especially focusing on the advantages and limitations of SSF and SmF processes.

Mitigation of acrylamide by l-asparaginase from Bacillus subtilis KDPS1 and analysis of degradation products by HPLC and HPTLC

The use of bacterial l-asparaginase (LA) is one of the alternative approaches for acrylamide reduction in food stuffs as it catalyzes the conversion of l-asparagine to l-aspartic acid and ammonia. In present investigation, purification of extracellular LA from isolate of Bacillus subtilis sp. strain KDPS-1 was carried out by solid state fermentation process. The effects of solid substrates, initial moisture content, moistening agents, temperature, and incubation time on LA production was studied, and the highest asparaginase activity (47 IU/ml) was achieved in the medium having orange peel as substrate. The enzyme was purified to homogeneity by diethylaminoethyl (DEAE) cellulose ion exchange chromatography; with 84.89 % yield and 12.11 fold purity. LA showed stimulant activity against β-mercaptoethanol and was greatly inhibited by Zn(2+) and Hg(2+) metal ions. Reduction of acrylamide in fried potatoes was detected by high performance liquid chromatography, which showed clear degradation of acrylamide by height and area (%) in the chromatograms of standard sample to that of the test sample. Hydrolysates analysis by high performance thin layer chromatography confirmed the test sample to be LA.

Studies on optimization of growth parameters for L-asparaginase production by Streptomyces ginsengisoli

A species of Streptomyces, Streptomyces ginsengisoli, a river isolate, was evaluated for production of an enzyme, L-asparaginase, with multiple functions mainly anticancer activity. The actinomycete was subjected to submerged fermentation by “shake flask” method. The quantity of L-asparaginase produced was estimated as 3.23 μmol/mL/min. The effect of various culture conditions on L-asparaginase production was studied by adopting a method of variation in one factor at a time. Of the various conditions tested, glucose (followed by starch) and peptone served as good carbon and nitrogen sources, respectively, for maximal production of enzyme at pH 8. The temperature of 30°C and an incubation period of 5 days with 0.05 g% asparagine concentration were found to be optimum for L-asparaginase production.

Marine enzymes

Marine enzyme biotechnology can offer novel biocatalysts with properties like high salt tolerance, hyperthermostability, barophilicity, cold adaptivity, and ease in large-scale cultivation. This review deals with the research and development work done on the occurrence, molecular biology, and bioprocessing of marine enzymes during the last decade. Exotic locations have been accessed for the search of novel enzymes. Scientists have isolated proteases and carbohydrases from deep sea hydrothermal vents. Cold active metabolic enzymes from psychrophilic marine microorganisms have received considerable research attention. Marine symbiont microorganisms growing in association with animals and plants were shown to produce enzymes of commercial interest. Microorganisms isolated from sediment and seawater have been the most widely studied, proteases, carbohydrases, and peroxidases being noteworthy. Enzymes from marine animals and plants were primarily studied for their metabolic roles, though proteases and peroxidases have found industrial applications. Novel techniques in molecular biology applied to assess the diversity of chitinases, nitrate, nitrite, ammonia-metabolizing, and pollutant-degrading enzymes are discussed. Genes encoding chitinases, proteases, and carbohydrases from microbial and animal sources have been cloned and characterized. Research on the bioprocessing of marine-derived enzymes, however, has been scanty, focusing mainly on the application of solid-state fermentation to the production of enzymes from microbial sources.

Antifungal efficacy of bacteria isolated from marine sedentary organisms

The antibiotic-producing ability of 57 bacteria isolated from 8 marine sedentary organisms, 6 sponges (Spirastrella sp., Phyllospongia sp., Ircinia sp., Aaptos sp., Azorica sp., Axinella sp.), 1 soft coral (Lobophytum sp.) and 1 alga (Sargassum sp.), was evaluated against 6 phytopathogenic fungi (Helminthosporium oryzae, Rhizoctonium solani, Pyricularia oryzae, Fusarium oxysporum, Aspergillus oryzae and A. fumigatus). Bacteria of the genus Bacillus (20%), Pseudomonas (33%) and Flavobacterium (40%) were predominant among the heterotrophic bacteria isolated from the marine sponges, soft coral and alga, respectively. Bioassay results revealed that 36 (63%) bacterial isolates displayed antifungal activity against at least one fungus, the alga (Sargassum sp.) being the source of highest number (80%) of producer strains. Twelve bacterial isolates inhibited all fungi. The MIC of the organic extracts of 12 bacteria ranged from 0.3 to 22.8 mg/L.

Production and properties of asparaginase from a new Erwinia sp

Asparaginase production by a mesophilic strain of Erwinia sp. was examined; the maximum of activity was found at 40 degrees C and pH 8.5. Among the various carbon sources, mannitol was shown to be the best for production of activity. Inorganic nitrogen sources were better than the organic ones. The enzyme activity was not inhibited by 10 mmol/L metal ions (Na+, K+, Mg2+, Ca2+, Ba2+, Co2+, Ni2+, Zn2+); the activity was strongly inhibited by addition of EDTA. L-Arginine, DL-alanine, L-asparagine and L-glutamine stimulated the L-asparaginase production by 3.9, 1.7, 4.3 and 4.0 fold, respectively. The combination of L-arginine, L-asparagine and L-glutamine synergistically stimulated the asparaginase up to 5.8 fold.