METABOLIC ENGINEERING
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2020
·
IF 7.263
Lin-Ping Yu,Xu Yan,Xu Zhang,Xiang-Bin Chen,Qiong Wu,Xiao-Ran Jiang,Guo-Qiang Chen
Polyhydroxyalkanoates (PHA) have found widespread medical applications due to their biocompatibility and biodegradability , while further chemical modification requires functional groups on PHA. Halomonas bluephagenesis , a non-model halophilic bacterium serving as a chassis for the Next Generation Industrial Biotechnology (NGIB), was successfully engineered to express heterologous PHA synthase (PhaC) and enoyl coenzyme-A hydratase (PhaJ) from Aeromonas hydrophila 4AK4, along with a deletion of its native phaC gene to synthesize the short chain- co -medium chain-length PHA copolymers , namely poly(3-hydroxybutyrate- co -3-hydroxyhexanoate), poly(3-hydroxybutyrate- co -3-hydroxyhex-5-enoate) and poly(3-hydroxybutyrate- co -3-hydroxyhexanoate- co -3-hydroxyhex-5-enoate). After optimizations of the expression cassette and ribosomal binding site combined with introduction of endogenous acyl-CoA synthetase ( fadD ), the resulting recombinant strain H. bluephagenesis TDR4 achieved a remarkably high 3-hydroxyhexenoate (3HHxE) molar ratio of 35% when grown on glucose and 5-hexenoic acid as co-substrates. The total ratio of side chain consisting of 3HHx and 3HHxE monomers in the terpolymer can approach 44 mol%. H. bluephagenesis TDR4 was grown to a cell dry mass (CDM) of 30 g/L containing approximately 20% poly(3-hydroxybutyrate- co -22.75 mol% 3-hydroxy-5-hexenoate) in a 48-h of open and unsterile fermentation with a 5-hexenoic acid conversion efficiency of 91%. The resulted functional PHA containing 12.5 mol% 3-hydroxy-5-hexenoate exhibits more than 1000% elongation at break. The engineered H. bluephagenesis TDR4 can be used as an experimental platform to produce functional PHA.
研究领域:
微生物学
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生物材料学
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合成生物学
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产品关联
DOI
PubMed
高影响因子
BIOTECHNOLOGY AND BIOENGINEERING
·
2024
·Vol. 121
·期 7
·2106-2120
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IF 3.5
Siqi Wang,Yujie Liu,Hongfu Guo,Yan Meng,Weini Xiong,Ruihua Liu,Chao Yang
Microbial production of polyhydroxyalkanoate (PHA) is greatly restricted by high production cost arising from high-temperature sterilization and expensive carbon sources. In this study, a low-cost PHA production platform was established from Halomonas cupida J9. First, a marker-less genome-editing system was developed in H. cupida J9. Subsequently, H. cupida J9 was engineered to efficiently utilize xylose for PHA biosynthesis by introducing a new xylose metabolism module and blocking xylonate production. The engineered strain J9UΔ xylD -P8 xylA has the highest PHA yield (2.81 g/L) obtained by Halomonas with xylose as the sole carbon source so far. This is the first report on the production of short- and medium-chain-length (SCL- co -MCL) PHA from xylose by Halomonas . Interestingly, J9UΔ xylD -P8 xylA was capable of efficiently utilizing glucose and xylose as co-carbon sources for PHA production. Furthermore, fed-batch fermentation of J9UΔ xylD -P8 xylA coupled to a glucose/xylose co-feeding strategy reached up to 12.57 g/L PHA in a 5-L bioreactor under open and unsterile condition. Utilization of corn straw hydrolysate as the carbon source by J9UΔ xylD -P8 xylA reached 7.0 g/L cell dry weight (CDW) and 2.45 g/L PHA in an open fermentation. In summary, unsterile production in combination with inexpensive feedstock highlights the potential of the engineered strain for the low-cost production of PHA from lignocellulose-rich agriculture waste.
研究领域:
微生物学
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生物工程
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环境科学
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DOI
PubMed
高影响因子
Frontiers of Environmental Science & Engineering
·
2021
·Vol. 16
·期 6
·1-10
·
IF 4.357
Man Quanli,Zhang Peilian,Huang Weiqi,Zhu Qing,He Xiaoling,Wei Dongsheng
A novel salt-tolerant heterotrophic nitrification and aerobic denitrification (HN-AD) bacterium was isolated and identified as Halomonas venusta TJPU05 ( H. venusta TJPU05). The nitrogen removal performance of H. venusta TJPU05 in simulated water (SW) with sole or mixed nitrogen sources and in actual wastewater (AW) with high concentration of salt and nitrogen was investigated. The results showed that 86.12% of NH 4 + -N, 95.68% of NO 3 − -N, 100% of NO 2 − -N and 84.57% of total nitrogen (TN) could be removed from SW with sole nitrogen sources within 24 h at the utmost. H. venusta TJPU05 could maximally remove 84.06% of NH 4 + -N, 92.33% of NO 3 − -N, 92.9% of NO 2 − -N and 77.73% of TN from SW with mixed nitrogen source when the salinity was above 8%. The application of H. venusta TJPU05 in treating AW with high salt and high ammonia nitrogen led to removal efficiencies of 50.96%, 47.28% and 43.19% for NH 4 + -N, NO 3 − -N and TN respectively without any optimization. Furthermore, the activities of nitrogen removal-related enzymes of the strain were also investigated. The successful detection of high level activities of ammonia oxygenase (AMO), hydroxylamine oxidase (HAO), nitrate reductase (NAR) and nitrite reductase (NIR) enzymes under high salinity condition further proved the HN-AD and salt-tolerance capacity of H. venusta TJPU05. These results demonstrated that the H. venusta TJPU05 has great potential in treating high-salinity nitrogenous wastewater.
研究领域:
微生物学
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环境科学
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DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
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2025
·
IF 8.5
Ziqian Wang,Chunyu Du,Ruyu Yan,Shuying Li,Guanyu Zheng,Dahu Ding
Polyhydroxyalkanoates (PHA) are promising candidates for replacing petroleum-derived plastics; however, their high production costs limit their commercialisation. In this study, we successfully isolated an efficient PHA-producing strain from a salt lake, which was subsequently identified as Halomonas sp. WZQ-1. Notably, Halomonas sp. WZQ-1 could serve as a promising cell-factory platform for polyhydroxybutyrate (PHB) production, achieving a comparatively high PHB productivity (7.64 ± 0.4 g L −1 ) under moderate salt stress (60 g L −1 NaCl). We further realised semi-continuous PHB production in a bench-scale fermenter at a steady state by irregularly replenishing the organic substrate. The maximum PHB concentration reached 12.13 g L −1 . Finally, we realised the non-sterile conversion of typical biowastes (e.g. pomelo and cantaloupe residues) to PHB using Halomonas sp. WZQ-1. Encouragingly, 4.36 g L −1 PHB was directly obtained from the hydrolysate of pomelo residues with a characteristic melting temperature of 174.0 °C. Life cycle assessment was employed to systematically evaluate the environmental sustainability and potential challenges of biowaste-driven PHB biorefineries. Overall, our findings could serve as a pivotal step toward the commercialisation of PHB and provide a valuable reference for PHB biorefineries.
研究领域:
微生物学
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环境科学
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生物技术
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产品关联
DOI
PubMed
高影响因子
Microbial Cell Factories
·
2024
·Vol. 23
·期 1
·1-12
·
IF 4.3
Chen Yaping,Liu Yujie,Meng Yan,Jiang Yuting,Xiong Weini,Wang Shufang,Yang Chao,Liu Ruihua
Background Ectoine as an amino acid derivative is widely applied in many fields, such as the food industry, cosmetic manufacturing, biologics, and therapeutic agent. Large-scale production of ectoine is mainly restricted by the cost of fermentation substrates (e.g., carbon sources) and sterilization. Results In this study, Halomonas cupida J9 was shown to be capable of synthesizing ectoine using xylose as the sole carbon source. A pathway was proposed in H. cupida J9 that synergistically utilizes both WBG xylose metabolism and EMP glucose metabolism for the synthesis of ectoine. Transcriptome analysis indicated that expression of ectoine biosynthesis module was enhanced under salt stress. Ectoine production by H. cupida J9 was enhanced by improving the expression of ectoine biosynthesis module, increasing the intracellular supply of the precursor oxaloacetate, and utilizing urea as the nitrogen source. The constructed J9U-P8EC achieved a record ectoine production of 4.12 g/L after 60 h of xylose fermentation. Finally, unsterile production of ectoine by J9U-P8EC from either a glucose-xylose mixture or corn straw hydrolysate was demonstrated, with an output of 8.55 g/L and 1.30 g/L of ectoine, respectively. Conclusions This study created a promising H. cupida J9-based cell factory for low-cost production of ectoine. Our results highlight the potential of J9U-P8EC to utilize lignocellulose-rich agriculture waste for open production of ectoine.
研究领域:
微生物学
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生物技术
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代谢工程
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DOI
PubMed
高影响因子
JOURNAL OF ENVIRONMENTAL MANAGEMENT
·
2026
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IF 9.2
Ziling Yuan,Yujie Liu,Haomin Chen,Jing Dang,Xinyu Zhang,Xinyao Li,Ruihua Liu,Chao Yang
Phenol and p -nitrophenol (PNP) are often co-detected in high-saline phenolic wastewater and combined toxicity caused by phenolic compounds poses potential risks to higher organisms, which have aroused serious concern for phenolic wastewater treatment. In this study, a halophilic bacterium Halomonas cupida J9 was engineered by genomic integration of phenol and PNP biodegradation pathways and the gfp gene (coding for green fluorescent protein), resulting in a fluorescently-labeled and halotolerant degrader (named J9U-PP). The transcription of all nine exogenous genes was achieved in strain J9U-PP. Strain J9U-PP was able to degrade 25 mg/L phenol in high-salt media containing 6% NaCl, and it also had the ability to degrade 25 to 100 mg/L PNP in high-salt media containing 6 to 10% NaCl. Moreover, strain J9U-PP was capable of mineralizing phenol and PNP to CO 2 in high-salt media. More importantly, co-mineralization of phenol and PNP by strain J9U-PP was verified in laboratory-amended wastewater samples. We demonstrate for the first time co-mineralization of phenol and PNP by an engineered halotolerant chassis. Strain J9U-PP can be easily tracked by green fluorescence in natural environments. Strain J9U-PP displayed superior growth kinetics and excellent genetic stability during passage culture. These merits make strain J9U-PP an ideal candidate for the remediation of hypersaline environments co-contaminated with phenol and PNP. This study suggests that constructing composite degradation circuits in an extremophile chassis may serve as a promising strategy for the remediation of extreme environments co-contaminated with multiple pollutants.
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DOI
PubMed
高影响因子
MOLECULES
·
2026
·Vol. 31
·期 18
·3215
·
IF 5.1
Rou Liu,Zirun Zhao,Guangbo Feng,Jiawen Yu,Xiaoxiang Zhou,Zijia Zhao,Danni Wang,Mingchun Li,Qilin Yu
Soil saline–alkali stress has become a great risk, leading to significant decline in crop yields, especially in protected agriculture that is frequently threatened by excessive chemical fertilization. There is an urgent need to develop friendly strategies for improving the quality of saline–alkali soil. Microbial inoculants are promising agents in attenuating soil stress, but their colonization ability in the crop rhizosphere is often limited. To improve the efficiency of microbial inoculants, this study constructed the assembly of a salt-tolerant bacterium Halomonas (Homs) and a hydrogel composed of sodium alginate, chitosan and xanthine with the assistance of artificial Homs-binding protein (Schx). The effect of this Homs + Schx assembly on the growth of crops and the rhizosphere microecology under saline–alkali stress was systematically evaluated by pot experiments. The results indicate that the application of Homs + Schx enhanced the Shannon index of the rhizosphere bacterial community and increased the relative abundance of key bacterial genera related to biofilm formation and nitrogen cycling (e.g., Curvibacter and Nitrospira ). Furthermore, Homs + Schx enhanced the activity of soil urease, peroxidase, and sucrase, reducing the sodium ion content, increasing the potassium ion content, and effectively lowering the soil pH and salt contents. Physiologically, this treatment induced a root osmotic regulatory response, resulting in an increase in the proline contents and a decrease in malondialdehyde contents. Consequently, Homs-Schx promoted the growth of tomatoes and wheat in saline–alkali soil. This study provides new ideas for enhancing the rhizosphere colonization of plant growth-promoting bacteria, regulating the structure of microbial communities, and enhancing crop stress tolerance with the aid of green material strategies.
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DOI
PubMed
高影响因子
Marine Life Science & Technology
·
2025
·
IF 5.3
Wang Yan,Wang Zhen,Zhao Wen-Xiao,Yuan Xiao-Jie,Yu Yang,Wang Peng,Wang Min,McMinn Andrew,Zhang Yu-Zhong,Peng Ming,Fu Hui-Hui,Chen Xiu-Lan
Free trans -4-hydroxy-L-proline (T4LHyp), a non-proteinogenic amino acid, is mainly released from the degradation of collagen, hydroxyproline-rich glycoproteins, and some peptide antibiotics in nature. Although it has been known that some terrestrial bacteria utilize T4LHyp as carbon and nitrogen source via a T4LHyp gene cluster, which and how marine microorganisms catabolize T4LHyp still remains unclear. Here, five T4LHyp-utilizing marine bacterial strains, Halomonas sp. 5021, Salinicola sp. 4072, Alteromonas sp. 6022, Alteromonas sp. 5112 and Alteromonas sp. 30521, were isolated from hydrothermal vent sediment samples collected from the southwest Indian Ocean. While Halomonas sp. 5021 can utilize T4LHyp as both a nitrogen and carbon source, the other four strains can utilize T4LHyp as only a nitrogen source. Then, the T4LHyp catabolic mechanisms of Halomonas sp. 5021 and Salinicola sp. 4072, as a representative of the four strains, were further investigated by genomic, transcriptional, and biochemical analyses. Halomonas sp. 5021 adopts an intact T4LHyp gene cluster containing four enzymes to catabolize T4LHyp into NH 3 and α-ketoglutarate to provide nitrogen and carbon sources for its growth. Compared to Halomonas sp. 5021, Salinicola sp. 4072 lacks an α-KGSA dehydrogenase gene in the T4LHyp gene cluster and can only catabolize T4LHyp into NH 3 and α-ketoglutarate semialdehyde to provide a nitrogen source for its growth. Bioinformatic investigation showed that the 5021-like and 4072-like T4LHyp gene clusters are predominantly found in bacteria from Pseudomonadota , which are widely distributed in multiple marine habitats. Thus, Pseudomonadota bacteria are likely the dominant group to drive the recycling and mineralization of T4LHyp in the ocean.
研究领域:
海洋微生物学
·
微生物生态学
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生物化学
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基因组学
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产品关联
DOI
PubMed
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
·
2023
·
IF 9.8
Zelin Hou,Qixing Zhou,Fan Mo,Weilu Kang,Shaohu Ouyang
Soil microbial communities are usually regarded as one of the key players in the global element cycling. Moreover, an important consequence of oil contamination altering the structure of microbial communities is likely to result in an increased carbon emission. However, understanding of the complex interactions between environmental factors and biological communities is clearly lagging behind. Here it showed that the flux of carbon emissions increased in oil-contaminated soils, up to 13.64 g C·(kg soil) −1 ·h −1 . This phenomenon was mainly driven by the enrichment of rare degrading microorganisms (e.g., Methylosinus , Marinobacter , Pseudomona s, Alcanivorax , Yeosuana , Halomonas and Microbulbifer ) in the aerobic layer, rather than the anaerobic layer, which is more conducive to methane formation. In addition, petroleum hydrocarbons and environmental factors are equally important in shaping the structure of microbial communities (the ecological stability) and functional traits (e.g., fatty acid metabolism, lipid metabolism and amino acid metabolism) due to the different ecological sensitivities of microorganisms. Thus, it can be believed that the variability of rare hydrocarbon degrading microorganisms is of greater concern than changes in dominant microorganisms in oil-contaminated soil. Undoubtedly, this study could reveal the unique characterization of bacterial communities that mediate carbon emission and provide evidence for understanding the conversion from carbon stores to carbon gas release in oil-contaminated soils.
研究领域:
环境科学
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微生物学
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生态学
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生物地球化学
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DOI
PubMed
高影响因子
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