Bioprospection of proteases from Halobacillus andaensis for bioactive peptide production from fish muscle protein

BACKGROUND: Biologically active peptides produced from fish wastes are gaining attention because their health benefits. Proteases produced by halophilic microorganisms are considered as a source of active enzymes in high salt systems like fish residues. Hence, the aim of this study was the bioprospection of halophilic microorganisms for the production of proteases to prove their application for peptide production. RESULTS: Halophilic microorganisms were isolated from saline soils of Mexico and Bolivia. An enzymatic screening was carried out for the detection of lipases, esterases, pHB depolymerases, chitinases, and proteases. Most of the strains were able to produce lipases, esterases, and proteases, and larger hydrolysis halos were detected for protease activity. Halobacillus andaensis was selected to be studied for proteolytic activity production; the microorganism was able to grow on gelatin, yeast extract, skim milk, casein, peptone, fish muscle (Cyprinus carpio), and soy flour as protein sources, and among these sources, fish muscle protein was the best inducer of proteolytic activity, achieving a protease production of 571 U/mL. The extracellular protease was active at 50°C, pH 8, and 1.4 M NaCl and was inhibited by phenylmethylsulfonyl fluoride. The proteolytic activity of H. andaensis was used to hydrolyze fish muscle protein for peptide production. The peptides obtained showed a MW of 5.3 kDa and a radical scavenging ability of 10 to 30% on 2,2-diphenyl-1-picrylhydrazyl and 2,2-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) and a ferric reducing ability of plasma. Conclusion: The use of noncommercial extracellular protease produced by H. andaensis for biologically active peptide production using fish muscle as the protein source presents a great opportunity for high-value peptide production.

Evaluation of Halobacterial Extracellular Hydrolytic Activities in Several Natural Saline and Hypersaline Lakes from Romania.

This work presents the evaluation of extracellular hydrolytic activities involved in the degrading of organic compounds from several natural salt lakes located in the southern part of Romania. The paper approaches the extracellular enzymatic decomposition activity in accordance with several physico-chemical parameters and microbial abundance. The chloride content was 13 g/l in Balta Albă salt lake, around 15 – 17 g/l in Amara salt lake, 80 g/l in Movila Miresei hypersaline lake and close to saturation, 252 g/l respectively in the case of Ocnele Mari hypersaline sample. The chemical composition revealed that salinity is due to compounds of sulphur, chloride and potassium in lakes Balta Alba and Amara. In Movila Miresei, potassium is replaced by sodium and in Ocnele Mari the salinity is due mainly to chloride and sodium. The enzyme α –glucosidase showed high values in the hypersaline lakes Movila Miresei and Ocnele Mari and a similar profile was recorded also for β-glucosidase. The activity of the enzyme alkaline phosphatase is directly correlated with the chloride content. The enzyme aminopeptidase showed high values if compared with previously mentioned enzymes.

Survey on Halophilic microbial diversity of Kovalam Saltpans in Kanyakumari District and its industrial applications.

Halophilic microorganisms are organisms that grow optimally in the presence of NaCl at least 0.2 M. The applications of halophilic bacteria include food and pharmaceutical industries, production of enzymes, polymers and various cosmetic products. The objective of the study was isolation and its characterization of potentially important microorganisms from saltpans. In this preliminary investigation, the total microbial counts were studied from the salt sample at three month intervals for one year. Totally 9 organisms were identified based on standard cultural, physiological and biochemical studies. These strains were subjected to screening of potential enzymes such as; amylase, protease, gelatinase, etc. The organisms Natranobacterium sp-1, Staphylococcus epidermidis, Staphylococcus intermedius and Staphylococcus citreus showed positive for amylase; Halo bacillus salinus, Halococcus salifodinae, Staphylococcus epidermidis and Staphylococcus intermedius showed positive for protease; Halobacillus salinus, Halobacterium salinarum, Natranobacterium sp-1, Staphylococcus intermedius and Staphylococcus citreus showed positive for gelatinase activity.

The Recent Advances in Halophilic Microorganisms for Environmental Bioremediation / 微生物学通报

As a result of various anthropogenic activities,natural saline environment polluted by contaminants and the environment polluted by both contaminants and salts frequently occur.In these saline environments,non-halophilic microorganisms have ineffective bioremediation,even lose the function of bioremediation.Halophilic microorganisms are able to thrive in high salt conditions.It is obvious that the halophilic degraders are more useful for the bioremediation of contaminated saline environments and may be potentially used in a wide of application.The objective of this review is to summarize the research progresses of halophiles in the biodegradation of petroleum hydrocarbons,aromatic hydrocarbon ramifications,and organophosphorous.