scholarly journals Substrate preferences, phylogenetic and biochemical properties of proteolytic bacteria present in the digestive tract of Nile tilapia

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.

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.


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 ◽  
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.


2014 ◽  
Vol 2014 ◽  
pp. 1-13 ◽  
Author(s):  
Yan-Ling Liang ◽  
Zheng Zhang ◽  
Min Wu ◽  
Yuan Wu ◽  
Jia-Xun Feng

From different natural reserves in the subtropical region of China, a total of 245 aerobic bacterial strains were isolated on agar plates containing sugarcane bagasse pulp as the sole carbon source. Of the 245 strains, 22 showed hydrolyzing zones on agar plates containing carboxymethyl cellulose after Congo-red staining. Molecular identification showed that the 22 strains belonged to 10 different genera, with theBurkholderiagenus exhibiting the highest strain diversity and accounting for 36.36% of all the 22 strains. Three isolates among the 22 strains showed higher carboxymethyl cellulase (CMCase) activity, and isolate ME27-1 exhibited the highest CMCase activity in liquid culture. The strain ME27-1 was identified asPaenibacillus terraeon the basis of 16S rRNA gene sequence analysis as well as physiological and biochemical properties. The optimum pH and temperature for CMCase activity produced by the strain ME27-1 were 5.5 and 50°C, respectively, and the enzyme was stable at a wide pH range of 5.0–9.5. A 12-fold improvement in the CMCase activity (2.08 U/mL) of ME27-1 was obtained under optimal conditions for CMCase production. Thus, this study provided further information about the diversity of cellulose-degrading bacteria in the subtropical region of China and foundP. terraeME27-1 to be highly cellulolytic.


2015 ◽  
Vol 64 (4) ◽  
pp. 369-377 ◽  
Author(s):  
Agnieszka Kalwasińska ◽  
Tamas Felfoldi ◽  
Maciej Walczak ◽  
Przemysław Kosobucki

This paper presents the results of the research on the number, taxonomic composition, and biochemical properties of bacterial strains isolated from the alkaline Solvay distillery lime, deposited at the repository in Janikowo (central Poland). Fifteen strains out of 17 were facultative alkaliphiles and moderate halophiles, and two were alkalitolerants and moderate halophiles. The number of aerobic bacteria cultured in alkaline lime was approximately 105 CFU ml-1, and the total number of bacteria was 107 cells g-1. According to 16S rRNA gene sequence analysis, nine strains belonged to the genus Bacillus, six to the genus Halomonas, one to the genus Planococcus, and one to the genus Microcella. Strains that hydrolyse starch and protein were the most numerous. Esterase (C4) and esterase lipase (C8) were detected in the majority of bacterial strains. Twelve strains exhibited α-glucosidase activity and nine, naphtol-AS-BI-phosphohydrolase activity. The present study proves that alkaliphilic bacteria of this type may constitute a source of potentially useful extremozymes.


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.


2014 ◽  
Vol 64 (Pt_7) ◽  
pp. 2431-2436 ◽  
Author(s):  
Xia Qiu ◽  
Zhihao Qu ◽  
Fan Jiang ◽  
Lvzhi Ren ◽  
Xulu Chang ◽  
...  

Two psychrotolerant, Gram-stain-negative, rod-shaped bacterial strains, designed M1-27T and 8-24T, were subjected to polyphasic taxonomic studies. Strain M1-27T was isolated from the foreland of the Midtre Lovénbreen glacier, whereas strain 8-24T was isolated from the foreland of the Austre Lovénbreen glacier. Both were Arctic glacier forelands, near Ny-Ålesund, Svalbard Archipelago, Norway. Strains M1-27T and 8-24T exhibited 16S rRNA gene sequence similarities of 91.0–96.0 % and 92.3–96.7 %, respectively, to type strains of recognized species of the genus Pedobacter . Phylogenetic analysis based on 16S rRNA gene sequences showed that the two strains were grouped with members of the genus Pedobacter, but represented distinct taxa. Both strains contained MK-7 as the predominant menaquinone. The DNA G+C contents of strains M1-27T and 8-24T were 43.8 % and 39.4 %, respectively. The phenotypic characteristics, biochemical properties and polygenetic analysis, clearly indicated that strains M1-27T ( = CCTCC AB 2012936T = LMG 28205T) and 8-24T ( = CCTCC AB 2012941T = NRRL B-59993T) represent two novel species of the genus Pedobacter , for which the names Pedobacter huanghensis sp. nov. and Pedobacter glacialis sp. nov., respectively, are proposed.


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.


Author(s):  
Safika Safika ◽  
Wenny Novita Sari ◽  
Gressha Vionalle Ademi ◽  
Ulfi Widi Arsih ◽  
Darmawi Darmawi

The aim of this study was to identify proteolytic bacteria from the ruminal and reticulum fluids of aceh cattle based on the 16S rRNA gene. Samples used were ruminal and reticulum fluids of aceh cattle slaughtered in Abattoir of Aceh Besar. Samples were diluted and cultured into Skim Milk Agar medium at 39 C for 48 hours. The morphology of bacterial colonies growth in the medium was observed. Colonies resulted in the largest clear zone were isolated and used for Deoxyribonucleic Acid (DNA) isolation, 16S rRNA gene amplification and sequencing. Theresults showed that morphology of dominant colonies was yellowish white color, round shape, position on the agar surface. The results ofphylogenetic analysis of RS1 and ReS2 isolates isolated from rumen and reticulum fluids of aceh cattle respectively had a close familialrelationship and belonged to the bacterial group of Kosakonia. Sequence homology showed isolate RS1 and ReS2 are probably either newEnterobacteriaceae species or unconfirmed species. Halo zone produced by ruminal bacteria had a wider diameter (25 mm vs 20 mm) than thatcaused by reticulum bacteria). Based on the results, RS1 (bacterium in the rumen) and ReS2 (bacterium in the reticulum) belong to similar type, namely Kosakonia sp. with a proteolytic activity. Presumably, these bacteria originate from the rumen that enters the reticulum with degraded feed.


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