Isolation and characterization of two novel ethanol-tolerant facultative-anaerobic thermophilic bacteria strains from waste compost

Fong, Jiunn C. N.; Svenson, Charles J.; Nakasugi, Kenlee; Leong, Caine T. C.; Bowman, John P.; Chen, Betty; Glenn, Dianne; Neilan, Brett A.; Rogers, Peter L.

doi:10.1007/s00792-006-0507-2

Cited by 59 publications

(35 citation statements)

References 62 publications

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“…In general, the product profiles are in line with other reports on thermophilic bacilli (23,33,34). Whereas these studies mainly focused on a particular species or strain, our data provide a comparison of several thermophilic Bacillus species and strains grown under the same conditions.…”

Section: Discussionsupporting

confidence: 90%

Isolation and Screening of Thermophilic Bacilli from Compost for Electrotransformation and Fermentation: Characterization of Bacillus smithii ET 138 as a New Biocatalyst

Bosma

Weijer

Daas

et al. 2015

Appl Environ Microbiol

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b Thermophilic bacteria are regarded as attractive production organisms for cost-efficient conversion of renewable resources to green chemicals, but their genetic accessibility is a major bottleneck in developing them into versatile platform organisms. In this study, we aimed to isolate thermophilic, facultatively anaerobic bacilli that are genetically accessible and have potential as platform organisms. From compost, we isolated 267 strains that produced acids from C 5 and C 6 sugars at temperatures of 55°C or 65°C. Subsequently, 44 strains that showed the highest production of acids were screened for genetic accessibility by electroporation. Two Geobacillus thermodenitrificans isolates and one Bacillus smithii isolate were found to be transformable with plasmid pNW33n. Of these, B. smithii ET 138 was the best-performing strain in laboratory-scale fermentations and was capable of producing organic acids from glucose as well as from xylose. It is an acidotolerant strain able to produce organic acids until a lower limit of approximately pH 4.5. As genetic accessibility of B. smithii had not been described previously, six other B. smithii strains from the DSMZ culture collection were tested for electroporation efficiencies, and we found the type strain DSM 4216 T and strain DSM 460 to be transformable. The transformation protocol for B. smithii isolate ET 138 was optimized to obtain approximately 5 ؋ 10 3 colonies per g plasmid pNW33n. Genetic accessibility combined with robust acid production capacities on C 5 and C 6 sugars at a relatively broad pH range make B. smithii ET 138 an attractive biocatalyst for the production of lactic acid and potentially other green chemicals. Green chemicals are sustainable bio-based alternatives for chemicals based on fossil resources. Biomass is considered an attractive renewable resource for the production of such green chemicals. Major challenges for using biomass are to develop costeffective production processes and to convert substrates that go beyond first-generation pure sugars. From this perspective, the use of microbial fermentation processes that convert lignocellulosic sugars is gaining considerable attention. For particular products natural producers can be used, but often Escherichia coli and Saccharomyces cerevisiae are used as platform organisms because of their well-known physiology and ease of engineering for the production of many different products (1, 2).In general, most organisms used for the production of green chemicals and fuels are mesophiles, and current processes still are based mainly on first-generation feedstocks, i.e., sucrose from sugar beet or sugarcane or glucose derived from starches from corn or tapioca. Although the engineering of platform organisms broadens the spectrum of possible substrates (3), the efficiency of the process could be increased by the use of organisms naturally capable of degrading lignocellulose-derived sugars (4). To further increase the efficiency and reduce the costs of the microbial production of green chemicals, modera...

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Section: Discussionsupporting

confidence: 90%

Isolation and Screening of Thermophilic Bacilli from Compost for Electrotransformation and Fermentation: Characterization of Bacillus smithii ET 138 as a New Biocatalyst

Bosma

Weijer

Daas

et al. 2015

Appl Environ Microbiol

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“…Members of this genus have been isolated from a wide range of environments, including temperate soils, as well as natural and artificial hot environments (4,21,35). This implies great environmental adaptability, which is supported by the remarkable properties of isolated Geobacillus species, such as ethanol tolerance (10), arsenate resistance (7), and the ability to degrade long-chain alkanes (35) and herbicides (21). Because of these properties, along with their thermophilicity and catabolic versatility, Geobacillus spp.…”

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confidence: 99%

Counterselection System for Geobacillus kaustophilus HTA426 through Disruption of pyrF and pyrR

Suzuki

Murakami

Yoshida

2012

Appl Environ Microbiol

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bCounterselection systems facilitate marker-free genetic modifications in microbes by enabling positive selections for both the introduction of a marker gene into the microbe and elimination of the marker from the microbe. Here we report a counterselection system for Geobacillus kaustophilus HTA426, established through simultaneous disruption of the pyrF and pyrR genes. The pyrF gene, essential for pyrimidine biosynthesis and metabolization of 5-fluoroorotic acid (5-FOA) to toxic metabolites, was disrupted by homologous recombination. The resultant MK54 strain (⌬pyrF) was auxotrophic for uracil and resistant to 5-FOA. MK54 complemented with pyrF was prototrophic for uracil but insensitive to 5-FOA in the presence of uracil. To confer 5-FOA sensitivity, the pyrR gene encoding an attenuator to repress pyrimidine biosynthesis by sensing uracil derivatives was disrupted. The resultant MK72 strain (⌬pyrF ⌬pyrR) was auxotrophic for uracil and resistant to 5-FOA. MK72 complemented with pyrF was prototrophic for uracil and 5-FOA sensitive even in the presence of uracil. The results suggested that pyrF could serve as a counterselection marker in MK72, which was demonstrated by efficient marker-free integrations of heterologous ␤-galactosidase and ␣-amylase genes. The integrated genes were functionally expressed in G. kaustophilus and conferred new functions on the thermophile. This report describes the first establishment of a pyrF-based counterselection system in a Bacillus-related bacterium, along with the first demonstration of homologous recombination and heterologous gene expression in G. kaustophilus. Our results also suggest a new strategy for establishment of counterselection systems.

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“…The recently characterized thermophile such as Geobacillus thermoglucosidasius M10EXG, isolated from waste compost, is considered as a potential strain for ethanol production, because this strain is tolerant to 10% (v/v) ethanol (Fong et al 2006). Study on the capability of the strain to utilise both glucose and xylose is essential as lignocelluloses comprise of hexose and pentose.…”

Section: Kinetic Evaluation Of Ethanol-tolerant Thermophile Geobacillmentioning

confidence: 99%

KINETIC EVALUATION OF ETHANOL-TOLERANT THERMOPHILE Geobacillus thermoglucosidasius M10EXG FOR ETHANOL PRODUCTION

Riyanti¹,

Rogers²

2016

Indones. J. Agric. Sci.

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Thermophiles are challenging to be studied for ethanol production using agricultural waste containing lignocellulosic materials rich in hexose and pentose. These bacteria have many advantages such as utilizing a wide range of substrates, including pentose (C5) and hexose (C6). In ethanol production, it is important to use ethanol tolerant strain capable in converting lignocellulosic hydrolysate. This study was aimed to investigate the growth profile of ethanol-tolerant thermophile Geobacillus thermoglucosidasius M10EXG using a defined growth medium consisted of single carbon glucose (TGTV), xylose (TXTV), and a mixture of glucose and xylose (TGXTV), together with the effect of yeast extract addition to the media. The experiments were conducted at

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Isolation and characterization of two novel ethanol-tolerant facultative-anaerobic thermophilic bacteria strains from waste compost

Cited by 59 publications

References 62 publications

Isolation and Screening of Thermophilic Bacilli from Compost for Electrotransformation and Fermentation: Characterization of Bacillus smithii ET 138 as a New Biocatalyst

Isolation and Screening of Thermophilic Bacilli from Compost for Electrotransformation and Fermentation: Characterization of Bacillus smithii ET 138 as a New Biocatalyst

Counterselection System for Geobacillus kaustophilus HTA426 through Disruption of pyrF and pyrR

KINETIC EVALUATION OF ETHANOL-TOLERANT THERMOPHILE Geobacillus thermoglucosidasius M10EXG FOR ETHANOL PRODUCTION

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