scholarly journals Isolation and selection of Bacillus sp. with the potential biosynthesis of protease from fermented soybean products

2021 ◽  
Vol 63 (8) ◽  
pp. 49-54
Author(s):  
Thi Ngoc Han Le ◽  
◽  
Thi Ngoc Diep Vo ◽  
Thi Tuyet Hoa Trinh ◽  
Van Thanh Nguyen ◽  
...  

This study aims to isolate and select strains of Bacillus for protease production from fermented soybean products. To evaluate the ability of protease production, the authors applied the hydrolysis diameter measurement method on Skim milk agar (SMA) and submerged fermentation (SmF). The results showed that 29 bacterial strains were isolated from fermented soybean products in An Giang and Can Tho provinces. Based on the morphological and biochemical characteristics of bacteria, these are defined belong to the Bacillus genus. The results of the protease generation test on SMA helped to select eight strains with a high halo diameter. In SmF with 106 cells/ml, pH 7.2, at 37°C for 48 hours, the ML01 strain gave the highest specific protease activity of 185.92 U/mg. Sequence analysis results of the 16S rRNA gene region of ML01 exhibited a high relationship with the sequence of Bacillus subtilis.

Author(s):  
Romina Belén Parada ◽  
Franco M. Sosa ◽  
Emilio R. Marguet ◽  
Marisol Marguet

A Gram-positive, facultatively anaerobic, gas-forming, catalase-negative, nonmotile, non-sporeforming, vancomycin-resistant, and ovoid-shaped bacterium, designated strain Tw234, was isolated from the intestinal tract of Parona leatherjacket (Parona signata). The strain grew in the presence of 0–6% (w/v) NaCl, at pH 3.5–8.5 and 8–40 °C; optimum growth was achieved at 1% (w/v) NaCl, at pH 6.0 and 30–32 °C. Exopolysacharides production was detected by the solidification test of skim milk supplemented with sucrose in the temperature range of 8 to 30 °C. Results of phylogenetic analysis based on the 16S rRNA gene sequence similarity indicated that strain Tw234 was closed related to the genus Leuconostoc and 100% homology with the type strain Ln. mesenteroides ssp. jonggajibkimchii DRC1506 (KCCM 43249, JCM 31787). The evaluation of growth and acidification rates were carried out in white cabbage and Chinese cabbage and compared with the strain Ln. mesenteroides ssp. jonggajibkimchii RCTw1.1, isolated from the spontaneous fermentation of red cabbage. No significant differences were observed between the behaviors of the two strains. The strain Tw234 displayed higher growth and acidification rates in controlled fermentation of white cabbage compared with those obtained in Chinese cabbage. New trends are targeted on the isolation and selection of strains to achieve controlled fermentation of vegetables that may ensure uniform quality. The results obtained in this work suggest that strain Tw234 harbored technological useful properties for its potential use as a starter in controlled vegetable fermentations.


2021 ◽  
Author(s):  
Tanim Jabid Hossain ◽  
Mukta Das ◽  
Ferdausi Ali ◽  
Sumaiya Islam Chowdhury ◽  
Subrina Akter Zedny

Abstract Vertebrate intestine appears an excellent source of proteolytic bacteria for industrial and probiotic use. We therefore aimed obtaining the gut-associated proteolytic species of Nile tilapia. We’ve isolated twenty six bacterial strains from its intestinal tract, seven of which showed exoprotease activity with the formation of clear halos on skim milk. Their depolymerization ability was further assessed on three distinct proteins including casein, gelatin and albumin. All the isolates could successfully hydrolyze the three substrates indicating relatively broad specificity of their secreted proteases. Molecular taxonomy and phylogeny of the proteolytic isolates were determined based on their 16S rRNA gene barcoding which suggested that the seven strains belong to three phyla viz. Firmicutes, Proteobacteria and Actinobacteria, distributed across the genera Priestia, Citrobacter, Pseudomonas, Stenotrophomonas, Burkholderia, Providencia and Micrococcus. The isolates were further characterized by a comprehensive study of their morphological, cultural, cellular and biochemical properties which were consistent with the phylogenetic annotations. To reveal their proteolytic capacity alongside substrate preferences, enzyme-production was determined by the diffusion assay. The Pseudomonas, Stenotrophomonas and Micrococcus isolates appeared most promising with maximum protease production on casein, gelatin and albumin media respectively. Our findings present valuable insights into the phylogenetic and biochemical properties of gut-associated proteolytic strains of Nile tilapia.


2014 ◽  
Vol 63 (3) ◽  
pp. 291-298
Author(s):  
ANNA LISEK ◽  
LIDIA SAS PASZ ◽  
PAWEŁ TRZCIŃSKI

Bacteria of the genus Pseudomonas are often components of bioproducts designed to enhance the condition of the soil and plants. The use of Pseudomonas bacteria in bioproducts must be preceded by the acquisition, characterization and selection of beneficial strains living in the soil. A prerequisite for the selection of bacterial strains for use in bioproducts is to be able to identify the isolates rapidly and accurately. To identify and differentiate 15 bacterial isolates obtained from the soil surrounding the roots of sour cherry trees and to assess their genetic similarity, the rep-PCR technique and restriction analysis of the 16S rRNA gene and the 16S-ITS-23S rRNA operon were used. In addition, a sequence analysis of the 16S rRNA gene was performed. The analyses made it possible to divide the isolates into four clusters and to confirm their affiliation with the Pseudomonas species. RFLP analysis of the 16S-ITS-23S rRNA operon enabled greater differentiation of the isolates than RFLP of the 16S rRNA gene. The greatest differentiation of isolates within the clusters was obtained after using the rep-PCR technique. However, none of the techniques was able to discriminate all the isolates, which indicates very high genetic similarity of the Pseudomonas isolates found in the same sample of soil from around the roots of sour cherry trees. The tests performed will find application for distinguishing and identifying Pseudomonas strains collected from the soil in order to select the most valuable bacterial strains that produce beneficial effects on plants.


2021 ◽  
Vol 7 (4) ◽  
pp. 528-545
Author(s):  
Tanim Jabid Hossain ◽  
◽  
Mukta Das ◽  
Ferdausi Ali ◽  
Sumaiya Islam Chowdhury ◽  
...  

<abstract> <p>Vertebrate intestine appears to be an excellent source of proteolytic bacteria for industrial and probiotic use. We therefore aimed at obtaining the gut-associated proteolytic species of Nile tilapia (<italic>Oreochromis niloticus</italic>). We have isolated twenty six bacterial strains from its intestinal tract, seven of which showed exoprotease activity with the formation of clear halos on skim milk. Their depolymerization ability was further assessed on three distinct proteins including casein, gelatin, and albumin. All the isolates could successfully hydrolyze the three substrates indicating relatively broad specificity of their secreted proteases. Molecular taxonomy and phylogeny of the proteolytic isolates were determined based on their 16S rRNA gene barcoding, which suggested that the seven strains belong to three phyla viz. Firmicutes, Proteobacteria, and Actinobacteria, distributed across the genera <italic>Priestia</italic>, <italic>Citrobacter</italic>, <italic>Pseudomonas</italic>, <italic>Stenotrophomonas</italic>, <italic>Burkholderia</italic>, <italic>Providencia</italic>, and <italic>Micrococcus</italic>. The isolates were further characterized by a comprehensive study of their morphological, cultural, cellular and biochemical properties which were consistent with the phylogenetic annotations. To reveal their proteolytic capacity alongside substrate preferences, enzyme-production was determined by the diffusion assay. The <italic>Pseudomonas</italic>, <italic>Stenotrophomonas</italic> and <italic>Micrococcus</italic> isolates appeared to be most promising with maximum protease production on casein, gelatin, and albumin media respectively. Our findings present valuable insights into the phylogenetic and biochemical properties of gut-associated proteolytic strains of Nile tilapia.</p> </abstract>


2021 ◽  
Author(s):  
Tanim Jabid Hossain ◽  
Mukta Das ◽  
Ferdausi Ali ◽  
Sumaiya Islam Chowdhury ◽  
Subrina Akter Zedny

Vertebrate intestine appears an excellent source of proteolytic bacteria for industrial and probiotic use. We therefore aimed obtaining the gut-associated proteolytic species of Nile tilapia. We have isolated twenty six bacterial strains from its intestinal tract, seven of which showed exoprotease activity with the formation of clear halos on skim milk. Their depolymerization ability was further assessed on three distinct proteins including casein, gelatin and albumin. All the isolates could successfully hydrolyze the three substrates indicating relatively broad specificity of their secreted proteases. Molecular taxonomy and phylogeny of the proteolytic isolates were determined based on their 16S rRNA gene barcoding which suggested that the seven strains belong to three phyla viz. Firmicutes, Proteobacteria and Actinobacteria, distributed across the genera Priestia, Citrobacter, Pseudomonas, Stenotrophomonas, Burkholderia, Providencia and Micrococcus. The isolates were further characterized by a comprehensive study of their morphological, cultural, cellular and biochemical properties which were consistent with the phylogenetic annotations. To reveal their proteolytic capacity alongside substrate preferences, enzyme-production was determined by the diffusion assay. The Pseudomonas, Stenotrophomonas and Micrococcus isolates appeared most promising with maximum protease production on casein, gelatin and albumin media respectively. Our findings present valuable insights into the phylogenetic and biochemical properties of gut-associated proteolytic strains of Nile tilapia.


2018 ◽  
Vol 94 (9) ◽  
Author(s):  
Yuki Saito ◽  
Tadashi Sato ◽  
Koji Nomoto ◽  
Hirokazu Tsuji

AbstractTo identify intestinal bacteria that produce phenols (phenol and p-cresol), we screened 153 strains within 152 species in 44 genera by culture-based assay using broth media supplemented with 200 µM each of tyrosine and its predicted microbial metabolic intermediates (4-hydroxyphenylpyruvate, DL-4-hydroxyphenyllactate, 3-(p-hydroxyphenyl)propionate, 4-hydroxyphenylacetate and 4-hydroxybenzoate). Phenol-producing activity was found in 36 strains and p-cresol-producing activity in 55 strains. Fourteen strains had both types of activity. Phylogenetic analysis based on the 16S rRNA gene sequences of strains that produced 100 µM or more of phenols revealed that 16 phenol producers belonged to the Coriobacteriaceae, Enterobacteriaceae, Fusobacteriaceae and Clostridium clusters I and XIVa; four p-cresol-producing bacteria belonged to the Coriobacteriaceae and Clostridium clusters XI and XIVa; and one strain producing both belonged to the Coriobacteriaceae. A genomic search for protein homologs of enzymes involved in the metabolism of tyrosine to phenols in 10 phenol producers and four p-cresol producers, the draft genomes of which were available in public databases, predicted that phenol producers harbored tyrosine phenol-lyase or hydroxyarylic acid decarboxylase, or both, and p-cresol producers harbored p-hydroxyphenylacetate decarboxylase or tyrosine lyase, or both. These results provide important information about the bacterial strains that contribute to production of phenols in the intestine.


2007 ◽  
Vol 57 (7) ◽  
pp. 1408-1412 ◽  
Author(s):  
Fred A. Rainey ◽  
Margarida Ferreira ◽  
M. Fernanda Nobre ◽  
Keren Ray ◽  
Danielle Bagaley ◽  
...  

Three ionizing-radiation-resistant bacterial strains (designated KR-196, KR-198 and KR-200T) were isolated from a sample of arid soil collected from a coastal desert in Chile. The soil sample was irradiated before serial dilution plating was performed using one-tenth-strength plate count agar. Phylogenetic analysis of the 16S rRNA gene sequences showed these organisms to represent a novel species of the genus Deinococcus, having sequence similarities of 87.3–90.8 % with respect to recognized Deinococcus species. Strains KR-196, KR-198 and KR-200T were aerobic and showed optimum growth at 30 °C and pH 6.5–8.0. The major respiratory menaquinone was MK-8. The predominant fatty acids in these strains were 16 : 1ω7c, 16 : 0, 15 : 1ω6c, 17 : 0 and 18 : 0. The DNA G+C content of strain KR-200T was 63.9 mol%. Strains KR-196, KR-198 and KR-200T were found to be resistant to >10 kGy gamma radiation. On the basis of the phylogenetic, chemotaxonomic and phenotypic data, strain KR-200T represents a novel species of the genus Deinococcus, for which the name Deinococcus peraridilitoris sp. nov. is proposed. The type strain is KR-200T (=LMG 22246T=CIP 109416T).


2007 ◽  
Vol 57 (8) ◽  
pp. 1815-1818 ◽  
Author(s):  
Kiyoung Lee ◽  
Yoe-Jin Choo ◽  
Stephen J. Giovannoni ◽  
Jang-Cheon Cho

Gram-negative, facultatively aerobic, chemoheterotrophic, short rod-shaped marine bacterial strains HTCC2662T and HTCC2663, isolated from the Sargasso Sea by using a dilution-to-extinction culturing method, were investigated to determine their taxonomic position. Characterization of the two strains by phenotypic and phylogenetic analyses revealed that they belonged to the same species. The DNA G+C content of strain HTCC2662T was 58.4 mol% and the predominant cellular fatty acids were C18 : 1 ω7c (52.5 %), C16 : 0 2-OH (13.5 %) and C18 : 1 11-methyl ω7c (12.2 %). Phylogenetic analysis of the 16S rRNA gene sequences showed that the strains represented a distinct line of descent within the genus Ruegeria, with highest sequence similarities to Ruegeria atlantica DSM 5823T (97.2 %), Ruegeria lacuscaerulensis DSM 11314T (96.5 %) and Ruegeria pomeroyi DSM 15171T (95.6 %). Several phenotypic characteristics, including facultatively requiring NaCl and oxygen for growth, together with the cellular fatty acid composition, differentiated strain HTCC2662T from other members of the genus Ruegeria. Based on phenotypic, chemotaxonomic and phylogenetic traits, it is suggested that strains HTCC2662T and HTCC2663 represent a novel species of the genus Ruegeria, for which the name Ruegeria pelagia sp. nov. is proposed. The type strain is HTCC2662T (=KCCM 42378T=NBRC 102038T).


2021 ◽  
Vol 69 (2) ◽  
Author(s):  
Jalcinês C. Pereira ◽  
Krystyna Gorlach-Lira ◽  
Bruno O. de Veras

Introduction: The coral-associated bacteria with antimicrobial activity may be important to promote the health of their host through various interactions, and may be explored as a source of new bioactive compounds. Objective: To analyze the antimicrobial activity of bacteria associated with the zoanthid Palythoa caribaeorum from the coral reefs of Carapibus, Paraiba state, Brazil. Methods: The phylogenetic analysis of the bacteria was conducted based on partial sequences of the 16S rRNA gene using molecular and bioinformatics tools. The antimicrobial activity of the 49 isolates was tested against four bacterial strains and one yeast strain: Bacillus cereus (CCT0198), Escherichia coli (ATCC 25922), Staphylococcus aureus (ATCC 25923), Pseudomonas aeruginosa and Candida albicans (ATCC 10231). The antibiosis and antibiogram assays were conducted and the Minimal Inhibitory Concentration (MIC) was determined by the microdilution method. Results: The bacterial isolates belonged to Firmicutes phylum (84 % of the isolates) and the Proteobacteria phylum (16 % of the isolates). Among the 49 isolates five genera were found, with the Bacillus genus being the most abundant (82 % of the isolates), followed by Vibrio (10 %), Pseudomonas (4 %), Staphylococcus (2 %) and Alteromonas (2 %). Antibiosis test revealed that 16 isolates (33 %) showed antimicrobial activity against one or more of five tested reference strains. The highest number of antagonistic bacteria were found in the Bacillus genus (12 isolates), followed by Vibrio (three isolates) and Pseudomonas (one isolate) genera. The B. subtilis NC8 was the only isolate that inhibited all tested strains in the antibiosis assay. However, antibiogram test with post-culture cell-free supernatant of NC8 isolate showed the inhibition of only B. cereus, S. aureus and C. albicans, and the lyophilized and dialyzed material of this isolate inhibited only B. cereus. The lyophilized material showed bacteriostatic activity against B. cereus, with a MIC value of 125 μg/μl, and in the cytotoxicity assay, the hemolysis value was of 4.8 %, indicating its low cytotoxicity. Conclusions: The results show the antimicrobial potential of some bacterial isolates associated with the P. caribaeourum tissue, especially those belonged to Bacillus genus.


2020 ◽  
Vol 2 (4) ◽  
pp. 13-23
Author(s):  
Nabiha Naeem Sheikhs ◽  
Qurat-ul-ain ◽  
Saba Altaf

Proteases (also known as peptidases or proteinases) are hydrolytic enzymes that cleave proteins into amino acids. They comprise 60% of the total industrial usage of enzymes worldwide and can be obtained from many sources. The current study aims to isolate and screen protease-producing bacterial strains from the soil and to produce protease from the bacterial co-cultures using solid-state fermentation (SSF). Primary screening of the protease-producing bacterial strains was carried out on skim milk agar and they were sub-cultured and preserved on the nutrient agar for further testing. Thirty-two compatibility tests of twenty-seven bacterial isolates were performed and SSF was carried out. Afterward, absorbance was taken at 660 nm against tyrosine as standard. According to the results, the bacterial co-culture 19 showed the highest absorbance with an enzyme activity of 10.2 U/ml. The bacterial strains of the co-culture 19 were identified through morphological and biochemical tests. Bacterial strain 1 was observed as cocci and irregular, while bacterial strain 2 was bacillus and rod-shaped. Both strains were positive for gram staining, catalase test, casein hydrolysis test and methyl red test. As for endospore staining, bacterial strain 1 was spore forming while bacterial strain 2 was a non-spore former. It was concluded that the bacterial co-culture 19 can act as a potent co-culture for protease production. Compatibility test was carried out to enhance the production of protease by utilizing cheap and readily available agro-waste products, which benefit the industry by being cost effective and the environment by being eco-friendly.


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