Microbial production of poly-γ-glutamic acid

Sirisansaneeyakul, Sarote; Cao, Mingfeng; Kongklom, Nuttawut; Chuensangjun, Chaniga; Shi, Zhongping; Chisti, Yusuf

doi:10.1007/s11274-017-2338-y

Cited by 70 publications

(59 citation statements)

References 61 publications

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“…At pH 7.0, the biomass achieved its highest value. This result was consistent with a previous literature [21]. We also investigated the effect of liquid volume on γ-PGA production, and found the production was decreased when the liquid volume increased (Fig.…”

Section: Orthogonal Test For Optimizing Fermentation Mediumsupporting

confidence: 93%

“…The glutamate-independent producer can use inorganic nitrogen sources for biosynthesizing γ-PGA [21].…”

Section: Effects Of Carbon and Nitrogen Sources On γ-Pga Productionmentioning

confidence: 99%

“…poly-γ-glutamic acid (γ-PGA)). γ-PGA is a natural anionic polymer of D/L-glutamic acids linked together via amide bonds between the α-amino group and the γ-carboxylic acid group, resulting in numerous properties, such as holding water, biodegradability and non-toxicity [20,21]. It has been widely used in food, medicine, cosmetic, and agriculture nowadays [22].…”

Section: Introductionmentioning

confidence: 99%

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Bioconversion of poly-γ-glutamic acid (γ-PGA) from fulvic acid powder produced from the wastewater of yeast molasses fermentation

Li¹,

Wang²,

Ke³

et al. 2020

Preprint

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Background: Molasses is a wildly used feedstock for fermentation, but it poses a severe wastewater-disposal problem worldwide. Recently, the wastewater produced by yeast during molasses fermentation is being processed into fulvic acid (FA) powder as a fertilizer for crops, but it consequently induces a problem of soil acidification after being directly applied in soil. In this study, the low-cost FA powder was bioconverted into a value-added product, γ-PGA, by a glutamate independent producer, Bacillus velezensis GJ11. Results: With FA powder, the substrates of sodium glutamate and citrate sodium used in medium were decreased around one third. Moreover, FA powder could completely substitute Mg2+, Mn2+, Ca2+ and Fe3+ in the fermentation medium. In the optimized FA powder fermentation medium, the γ-PGA was produced with its maximum concentration at 42.55 g/L and a productivity of 1.15 g/(L·h), while only 2.87 g/L was produced in the medium without FA powder. Hydrolyzed γ-PGA could trigger induced systemic resistance (ISR), e.g. H2O2 accumulation and callose deposition, against the pathogen infection in plants. Further investigations found that the ISR triggered by γ-PGA hydrolyzates was dependent on the ethylene signalling and NPR1. Conclusions: To our knowledge, this is the first report of using the industry waste, FA powder, as a sustainable substrate for the microbial synthesis of γ-PGA. This bioprocess can not only develop a new way of FA powder as a cheap feedstock for producing γ-PGA, but also help to reduce pollution from the wastewater of yeast molasses fermentation.

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Section: Orthogonal Test For Optimizing Fermentation Mediumsupporting

confidence: 93%

“…The glutamate-independent producer can use inorganic nitrogen sources for biosynthesizing γ-PGA [21].…”

Section: Effects Of Carbon and Nitrogen Sources On γ-Pga Productionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Bioconversion of poly-γ-glutamic acid (γ-PGA) from fulvic acid powder produced from the wastewater of yeast molasses fermentation

Li¹,

Wang²,

Ke³

et al. 2020

Preprint

View full text Add to dashboard Cite

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“…Bacillus strains are important for the production of various industrial biochemical products, including poly-␥-glutamic acid (36), the broad-spectrum antibiotic bacitracin (37), and 2,3-butanediol (38). However, a lack of tools for genetic manipulation has hindered their development.…”

Section: Discussionmentioning

confidence: 99%

Development of an Efficient Genome Editing Tool in Bacillus licheniformis Using CRISPR-Cas9 Nickase

Cai

Wang

et al. 2018

Appl Environ Microbiol

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strains are important industrial bacteria that can produce various biochemical products. However, low transformation efficiencies and a lack of effective genome editing tools have hindered its widespread application. Recently, clustered regularly interspaced short palindromic repeat (CRISPR)-Cas9 techniques have been utilized in many organisms as genome editing tools because of their high efficiency and easy manipulation. In this study, an efficient genome editing method was developed for using a CRISPR-Cas9 nickase integrated into the genome of DW2 with overexpression driven by the P43 promoter. The gene was deleted using the CRISPR-Cas9n technique with homology arms of 1.0 kb as a representative example, and an efficiency of 100% was achieved. In addition, two genes were simultaneously disrupted with an efficiency of 11.6%, and the large DNA fragment (42.7 kb) was deleted with an efficiency of 79.0%. Furthermore, the heterologous reporter gene , which codes for nattokinase in, was inserted into the chromosome of with an efficiency of 76.5%. The activity of nattokinase in the DWc9nΔ7/pP43SNT-S strain reached 59.7 fibrinolytic units (FU)/ml, which was 25.7% higher than that of DWc9n/pP43SNT-S Finally, the engineered strain DWc9nΔ7 (Δ Δ Δ Δ Δ Δ Δ), with multiple disrupted genes, was constructed using the CRISPR-Cas9n technique. Taken together, we have developed an efficient genome editing tool based on CRISPR-Cas9n in This tool could be applied to strain improvement for future research. As important industrial bacteria, strains have attracted significant attention due to their production of biological products. However, genetic manipulation of these bacteria is difficult. The CRISPR-Cas9 system has been applied to genome editing in some bacteria, and CRISPR-Cas9n was proven to be an efficient and precise tool in previous reports. The significance of our research is the development of an efficient, more precise, and systematic genome editing method for single-gene deletion, multiple-gene disruption, large DNA fragment deletion, and single-gene integration in via Cas9 nickase. We also applied this method to the genetic engineering of the host strain for protein expression.

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“…Microbes generate glutamic acid-dependent (c-PGA), which usually need glutamic acid in the media for inducing c-PGA synthetase [7,8] and others glutamic acid-independent that produce PGA without D-glutamic acid [9,4]. The glutamic acidindependent bacteria have a lower PGA productivity compared to glutamic aciddependent bacteria [10]. Therefore, the accumulation of PGA biopolymer in the media usually increases when L-glutamic acid used as a nutrient, so this modification is expensive [11,12].…”

Section: Introductionmentioning

confidence: 99%

Isolation, Identification and Evaluation of Egyptian Bacillus sp. Isolates for Producing Poly-γ-glutamic Acid

Ahmed

Khalil

2020

JAMB

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Poly-γ-glutamic acid (γ-PGA) is a non-toxic, biodegradable, and water-soluble polymer secreted from different microbes. We isolated forty-nine Bacillus spp. isolates generating PGA from the soil of different Egyptian regions. A total of 18% of these isolates were found to highly produce PGA in the range of 5- 8 gl-l. Two of them, B44 and B42, were identified by the16SrRNA DNA sequence, and they shared 81% of similarity. The most similar DNA sequences to B44-16SrRNA were Bacillus sp. (FJ607057.1) and Bacillus sonorensis (KP236346.1) matching 99% and 94% of similarity, respectively. However, B42-16SrRNA was similar 99% to several Bacillus species. The tree-building algorithm MEGA-X constructed the phylogenetic tree of 16SrRNA DNA sequences for Bacillus 44 and Bacillus 42 strains along with other similar Bacillus species revealing the distance between them. We also boosted the PGA production of both strains. Bacillus 44 strain revealed the highest accumulation level of PGA at 35°C and 72 h of incubation using medium M with inoculum size and agitation speed 3% and 250 rpm, respectively. Both strains secreted the PGA biopolymer with a molecular mass of 55 kDa. This investigation is an attempt of boosting promising Egyptian Bacillus sp. isolates for PGA production that may be a seed for industrial production.

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Microbial production of poly-γ-glutamic acid

Cited by 70 publications

References 61 publications

Bioconversion of poly-γ-glutamic acid (γ-PGA) from fulvic acid powder produced from the wastewater of yeast molasses fermentation

Bioconversion of poly-γ-glutamic acid (γ-PGA) from fulvic acid powder produced from the wastewater of yeast molasses fermentation

Development of an Efficient Genome Editing Tool in Bacillus licheniformis Using CRISPR-Cas9 Nickase

Isolation, Identification and Evaluation of Egyptian Bacillus sp. Isolates for Producing Poly-γ-glutamic Acid

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