Activity, molecular mass and hydrolysis on baker's yeast protein of extracellular proteases from the putative probiotic bacteria Microbacterium sp. strain 8L and Exiguobacterium mexicanum strain 8N

Abstract

The bacteria Microbacterium sp. 8L and Exiguobacterium mexicanum 8N are known to improve the culture of Artemia franciscana using baker's yeast as food. Using spectrophotometry, sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS‐PAGE), substrate‐SDS‐PAGE and pH‐stat in vitro‐digestibility assays, the activity, molecular mass and hydrolysis on baker's yeast protein of proteases from extracellular polymeric substances (EPS) of the strains 8L and 8N along with the pathogenic strains Microbacterium sp. 8R and Vibrio parahaemolyticus 588 CECT (Vp) were studied. The EPSs of 8L and 8R showed one activity band, on which the serine inhibitor phenylmethylsulphonyl fluoride (PMSF) had no effect. The EPSs of 8N showed four bands; two were unaffected by PMSF, whereas one was affected, and the other was partially affected. The EPSs of Vp showed two bands, one partially inhibited by PMSF. No inhibitory effects from 1‐chloro‐3‐tosylamido‐7‐amino‐2‐heptanone (trypsin inhibitor) were observed in the protease bands of the studied bacteria. The EPSs of 8L and 8N showed a similar degree of hydrolysis (pH‐stat). The EPSs of 8L had the lowest Dice index of similarity of yeast protein profiles at 1 h of reaction. We conclude that the strain 8L could benefit A. franciscana by providing bacterial proteases for digestion of baker's yeast.

Habitat and indigenous gut microbes contribute to the plasticity of gut microbiome in oriental river prawn during rapid environmental change

“…can significantly improve shrimp larval survival and is considered to be a novel probiotic bacteria [ 48 ], yet it remains a challenge to investigate to what extent other environmental bacteria contribute to their host phenomic plasticity. Otherwise, in river-to-lake shrimp, we observed the family Incertae Sedis XII within the order Bacillales , among which all reads were classified to genus Exiguobacterium , which is also one of the putative probiotics in aquatic environments [ 49 ], and its sister genus Bacillus has been widely used as a probiotic for aquaculture [ 50 ]. These species of bacteria are commonly found in water and sediments and therefore are naturally ingested by shrimp that feed in or on the environmental material.…”

Accumulation of 5-methyltetrahydrofolate and other bioactive compounds, in the course of fermentation of green tea (Camellia sinensis) kombucha

“…Previous studies have also reported isolates of this genus in kombucha beverage or polymeric disc, strengthening the association of these species with this beverage [ [44] , [45] , [46] ]. Some species of Microbacterium genus showed probiotic features in animal models [ 47 ], including mammals [ 48 ], and might produce antioxidants [ 49 ] and antimicrobial compounds [ 50 ]. More studies are necessary to ascertain which of these properties can be attributed to the species found in kombucha.…”

Proteolytic, Lipolytic and Amylolytic Bacteria Reservoir of Turkey; Cold-Adaptive Bacteria in Detergent Industry

“…It was gram, catalase and oxidase positive, motile and endospore negative. Orozco-Medina et al 37 were studied on protease production of E. mexicanum and Venkatachalam et al 38 were able to produce cold-adaptive protease, amylase and lipase form E. mexicanum.…”