Screening and Characterization of Thermostable Amylase-Producing Bacteria Isolated from Soil Samples of Afdera, Afar Region, and Molecular Detection of Amylase-Coding Gene

Yassin, Semira Nureddin; Jiru, Tamene Milkessa; Indracanti, Meera

doi:10.1155/2021/5592885

Cited by 27 publications

(18 citation statements)

References 26 publications

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“…The three isolates, namely, Isolate 1-Rhizosphere root nodules, Isolate 2-, Lake soil sample and Isolate 3-Garbage soil sample were found to be Gram negative long or short rods [15]. Gram-negative bacteria are usually E. coli, Klebsiella, Acinetobacter, and Pseudomonas spp.…”

Section: Resultsmentioning

confidence: 94%

Isolation and characterization of starch degrading bacteria from disparate soil samples

Srivathsan¹,

Bhandari²,

Swaminathan³

2022

J App Biol biotech

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Amylases are starch degrading enzymes. These enzymes play a pivotal role in the biotechnology industries in food, fermentation, textiles, and paper production. Many industries lack local amylase supply, so the demand for amylase is often high. The study focuses on the screening and isolation of amylase producing bacteria from disparate samples of soil. The promising hydrolytic strains of bacteria from the collected samples were characterized using enzyme kinetics and further investigation is carried out to characterize the amylase enzyme produced by optimization of pH and temperature. The shortlisted isolate was identified using 16s rRNA sequencing. This study is an initial result of an exploration where soil is a source of industrially important amylase producing bacterial strains.

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Section: Resultsmentioning

confidence: 94%

Isolation and characterization of starch degrading bacteria from disparate soil samples

Srivathsan¹,

Bhandari²,

Swaminathan³

2022

J App Biol biotech

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“…However, an increase in amylase production was observed with 0.5-3% starch concentration, and a decline in production was observed with an increase in a concentration above 3% substrate. Perhaps this is due to the culture's ability to metabolize starch in such a short amount of time when the starch content was increased [43]. The current study's ndings are superior to other halophilic organisms such as Bacillus cereus MS6 (2% starch) [44] and Haloferax sp.…”

Section: Identi Cation and Characterization Of Amylase Producing Bact...mentioning

confidence: 80%

A Novel Starch Digesting Halo-Acid-Alkali-Tolerant and Surfactant Stable Amylase from Newly Isolated Halophilic Bacterium Bacillus Siamensis Sp. F2: Application in Waste Valorization to Ethanol Fermentation

Rathod¹,

Pandala²,

Poosarla³

2022

Preprint

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The extracellular amylase production level by the moderate halophile Bacillus siamensis sp. F2 was optimized, and the enzyme was biochemically characterized. The culture parameters for NaCl, carbon, nitrogen, pH, and temperature were optimized for high titers of amylase production. Growing Bacillus siamensis sp. F2 cultures in Great Salt Lake-2 medium with additions of (in g/l) NaCl (100), starch (30), yeast extract (2), KNO3 (2), and MgSO4 (1) at pH 8, 30°C resulted in the maximum amylase production (4.2 U/ml). The amylase was active across a wide range of salinities (0 to 30% NaCl), pH (5.0–10.0), and temperatures (20–70oC), and showed good stability with surfactants (SDS and Triton X-100); hence identified as halo-acid-alkali-tolerant and surfactant stable. Temperature, pH, and salinity were optimal for amylase activity at 50°C, pH 7, and 5% NaCl, respectively. It also generates amylase utilizing agricultural wastes like sugarcane bagasse, wheat bran, and rice husk. Based on the performance of Bacillus siamensis sp. F2 using sugarcane bagasse and synthesizing amylase, the current study attempted to produce bioethanol by co-culturing with baker's yeast, which yielded 157 g/L of bioethanol. This novel amylase may have many potential applications in industrial waste-valorization and biorefinery sectors.

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“…Starch hydrolysis was examined by fumigating the plates with iodine for 1 minute [ 31 ], and positive bacterial colonies with amylase activity were selected through visible hydrolytic circles against a dark blue background. The colonies showing a clear difference in morphology were further purified by subculture on amylase-screening TSA plates until a monoclonal cell of uniform morphology and size was observed [ 32 ]. The pure isolates were transferred to TSB and incubated at 28°C at 220 rpm for 16–18 hours.…”

Section: Methodsmentioning

confidence: 99%

“…After incubation at 28°C for 15 minutes, the DNS reagent was boiled for 10 minutes to develop color and then cooled to room temperature. The release of reducing sugars was determined spectrophotometrically at 540 nm [ 32 , 40 ]. One unit of amylase in our assay was defined as the amount of enzyme that liberated 1.0 µ mol of reducing sugar per minute in 1.0 mL of crude enzyme solution under certain assay conditions.…”

Section: Methodsmentioning

confidence: 99%

Activity-Based Screening of Soil Samples from Nyingchi, Tibet, for Amylase-Producing Bacteria and Other Multifunctional Enzyme Capacities

Liu

Guo

Lü

et al. 2022

International Journal of Microbiology

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Despite the interest in Tibetan soil as a promising source of functional enzymes with potential biotechnological applications, few studies have considered the screening and identification of amylase producing bacteria from Tibetan soil. Amylase has many applications in the food and feed industries, textile and biofuel production, and biomedical engineering. The area of amylase with specific properties is attracting growing attention because of its better application to various industrial conditions. This study aims to screen and identify amylase-producing strains from soil samples collected in Nyingchi, Tibet, and then explore whether the bacterial isolates are superior for unique enzymes. In this paper, a total of 127 amylase producing bacteria were isolated by activity-based screening of six Tibetan soil samples. The 16S rRNA gene survey then identified four major phyla, namely, firmicutes, bacteroidetes, proteobacteria, and actinobacteria, which were differentiated into twelve genera with a dominance of Bacillus (67.72%), followed by Pseudomonas (8.66%). Microbial diversity analysis revealed that the amylase-producing bacterial community of the Kadinggou forest soil sample showed the best variety (the Simpson index was 0.69 and the Shannon index was 0.85). The amylase activity assay of the bacterial isolates showed a mean of 0.66 U/mL at 28°C and pH 5.2. Based on the effect of temperatures and pHs on amylase activity, several bacterial isolates can produce thermophilic (50°C), psychrophilic (10°C), acidophilic (pH 4.2), and alkaliphilic (pH 10.2) amylases. Furthermore, four bacterial isolates were screened for amylase, protease, and esterase activities, which indicated multifunctional enzyme capacities. The present study is expected to contribute to our understanding of Tibetan microbial resources and their potential for scientific research and industrial applications.

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Screening and Characterization of Thermostable Amylase-Producing Bacteria Isolated from Soil Samples of Afdera, Afar Region, and Molecular Detection of Amylase-Coding Gene

Cited by 27 publications

References 26 publications

Isolation and characterization of starch degrading bacteria from disparate soil samples

Isolation and characterization of starch degrading bacteria from disparate soil samples

A Novel Starch Digesting Halo-Acid-Alkali-Tolerant and Surfactant Stable Amylase from Newly Isolated Halophilic Bacterium Bacillus Siamensis Sp. F2: Application in Waste Valorization to Ethanol Fermentation

Activity-Based Screening of Soil Samples from Nyingchi, Tibet, for Amylase-Producing Bacteria and Other Multifunctional Enzyme Capacities

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