Glyphosate is a widely used herbicide with an annual production of more than one million tons globally. Current commercialized production processes of glyphosate are generally associated with ...manufacturing hazards and toxic wastes. Recently, many countries have strengthened environmental supervision and law enforcement on glyphosate manufacturing. Therefore, a green source of glyphosate is required. Here, we characterize the genes required for producing aminomethylphosphonate (AMP), one of the intermediates in the biosynthesis of the potent antibiotics argolaphos. We apply a synthetic biology strategy to improve AMP production in Streptomyces lividans, with fermentation titers of 52 mg L
, a 500-fold improvement over the original strain. Furthermore, we develop an efficient and practical chemical process for converting AMP to glyphosate. Our findings highlight one greenness-driven alternative in the production of glyphosate.
Cyclic peptide natural products represent an important class of bioactive compounds and clinical drugs. Enzymatic side-chain macrocyclization of ribosomal peptides is a major strategy developed by ...nature to generate these chemotypes, as exemplified by the superfamily of ribosomally synthesized and post-translational modified peptides. Despite the diverse types of side-chain crosslinks in this superfamily, the participation of histidine residues is rare. Herein, we report the discovery and biosynthesis of bacteria-derived tricyclic lanthipeptide noursin, which is constrained by a tri amino acid labionin crosslink and an unprecedented histidine-to-butyrine crosslink, named histidinobutyrine. Noursin displays copper-binding ability that requires the histidinobutyrine crosslink and represents the first copper-binding lanthipeptide. A subgroup of lanthipeptide synthetases, named LanKC
, were identified to catalyze the formation of both the labionin and the histidinobutyrine crosslinks in precursor peptides and produce noursin-like compounds. The discovery of the histidinobutyrine-containing lanthipeptides expands the scope of post-translational modifications, structural diversity and bioactivity of ribosomally synthesized and post-translational modified peptides.
Abstract Xenocoumacin 1 (Xcn 1), antibiotic discovered from secondary metabolites of Xenorhabdus nematophila , had the potential to develop into a new pesticide due to its excellent activity against ...bacteria, oomycetes and fungi. However, the current low yield of Xcn1 limits its development and utilization. To improve the yield of Xcn1, response surface methodology was used to determine the optimal composition of fermentation medium and one factor at a time approach was utilized to optimize the fermentation process. The optimal medium composed of in g/L: proteose peptone 20.8; maltose 12.74; K 2 HPO 4 3.77. The optimal fermentation conditions were that 25 °C, initial pH 7.0, inoculum size 10%, culture medium 75 mL in a 250 mL shake flask with an agitation rate of 150 rpm for 48 h. Xenorhabdus nematophila YL001 was produced the highest Xcn1 yield (173.99 mg/L) when arginine was added to the broth with 3 mmol/L at the 12th h. Compared with Tryptic Soy Broth medium, the optimized fermentation process resulted in a 243.38% increase in Xcn1 production. The obtained results confirmed that optimizing fermentation technology led to an increase in Xcn1 yield. This work would be helpful for efficient Xcn1 production and lay a foundation for its industrial production.
Relative to the atmosphere, much of the aerobic ocean is supersaturated with methane; however, the source of this important greenhouse gas remains enigmatic. Catabolism of methylphosphonic acid by ...phosphorus-starved marine microbes, with concomitant release of methane, has been suggested to explain this phenomenon, yet methylphosphonate is not a known natural product, nor has it been detected in natural systems. Further, its synthesis from known natural products would require unknown biochemistry. Here we show that the marine archaeon Nitrosopumilus maritimus encodes a pathway for methylphosphonate biosynthesis and that it produces cell-associated methylphosphonate esters. The abundance of a key gene in this pathway in metagenomic data sets suggests that methylphosphonate biosynthesis is relatively common in marine microbes, providing a plausible explanation for the methane paradox.
Although natural products have been a particularly rich source of human medicines, activity-based screening results in a very high rate of rediscovery of known molecules. Based on the large number of ...natural product biosynthetic genes in microbial genomes, many have proposed “genome mining” as an alternative approach for discovery efforts; however, this idea has yet to be performed experimentally on a large scale. Here, we demonstrate the feasibility of large-scale, high-throughput genome mining by screening a collection of over 10,000 actinomycetes for the genetic potential to make phosphonic acids, a class of natural products with diverse and useful bioactivities. Genome sequencing identified a diverse collection of phosphonate biosynthetic gene clusters within 278 strains. These clusters were classified into 64 distinct groups, of which 55 are likely to direct the synthesis of unknown compounds. Characterization of strains within five of these groups resulted in the discovery of a new archetypical pathway for phosphonate biosynthesis, the first (to our knowledge) dedicated pathway for H-phosphinates, and 11 previously undescribed phosphonic acid natural products. Among these compounds are argolaphos, a broad-spectrum antibacterial phosphonopeptide composed of aminomethylphosphonate in peptide linkage to a rare amino acid N5-hydroxyarginine; valinophos, an N-acetyl L-Val ester of 2,3-dihydroxypropylphosphonate; and phosphonocystoximate, an unusual thiohydroximate-containing molecule representing a new chemotype of sulfur-containing phosphonate natural products. Analysis of the genome sequences from the remaining strains suggests that the majority of the phosphonate biosynthetic repertoire of Actinobacteria has been captured at the gene level. This dereplicated strain collection now provides a reservoir of numerous, as yet undiscovered, phosphonate natural products.
Pigs have played a major role in the economic, social and symbolic systems of China since the Early Neolithic more than 8,000 years ago. However, the interaction between the history of pig ...domestication and transformations in Chinese society since then, have not been fully explored. In this paper, we investigated the co-evolution from the earliest farming communities through to the new political and economic models of state-like societies, up to the Chinese Empire, using 5,000 years of archaeological records from the Xiawanggang (XWG) and Xinzhai (XZ) sites (Henan Province). To trace the changes of pig populations against husbandry practices, we combined the geometric morphometric analysis of dental traits with a study of the stable carbon and nitrogen isotope ratios from bone collagen. The domestication process intensified during the Neolithic Yangshao, prompted by greater selective pressure and/or better herd control against wild introgression. After that, pig farming, in XWG, relied on local livestock and a gradual change of husbandry practices overtime. This was characterized by a gentle increase in millet foddering and animal protein intake, until a complete change over to household management during the Han dynasty. The only rupture in this steady trend of husbandry occurred during the Longshan period, with the appearance of small sized and idiosyncratic pigs with specific feeding practices (relying on millet and household scraps). From three exploratory hypothesis, we explored the possibility of anti-elite pig production in XWG during the Longshan period, as a means to resist incorporation into a new economic model promoting intensified domestic production. This exploratory hypothesis is the most suitable to our dataset; however, numerous areas need to be explored further in order to adequately document the role of pigs in the rise of China's complex societies.
The ancestor of all modern domestic cats is the wildcat, Felis silvestris lybica, with archaeological evidence indicating it was domesticated as early as 10,000 years ago in South-West Asia. A recent ...study, however, claims that cat domestication also occurred in China some 5,000 years ago and involved the same wildcat ancestor (F. silvestris). The application of geometric morphometric analyses to ancient small felid bones from China dating between 5,500 to 4,900 BP, instead reveal these and other remains to be that of the leopard cat (Prionailurus bengalensis). These data clearly indicate that the origins of a human-cat 'domestic' relationship in Neolithic China began independently from South-West Asia and involved a different wild felid species altogether. The leopard cat's 'domestic' status, however, appears to have been short-lived--its apparent subsequent replacement shown by the fact that today all domestic cats in China are genetically related to F. silvestris.
Abstract
In this paper, a novel low-cost and lightweight lithium ion batteries thermal design based on EG-based composite phase change material to store heat under normal EV operating conditions is ...developed and verified theoretically. The three dimensional thermal simulation model is proposed to compute the transient temperature of the battery at some actual driving conditions during discharge. The capability of battery thermal management system based on composite PCM under four kinds of actual electric vehicles thermal safety evaluation condition is investigated, and some factors influencing the system are discussed in detail. Simulation results show that the temperature of the lithium ion battery can be maintained within a reasonable range by adopting the cooling system. The highest temperature of battery discharging at 1C rate can be kept no more than 45.1 °C in the cost of 0.5mm in thickness and 1.02kg in weight increment of PCM and the temperature consistency evaluation methods based on integral values were proposed. The conclusions got in this paper can be valuable reference for battery thermal management design and analysis of dissipating heat against daily driving discharge condition.
Bioassay-guided fractionation of Cladosporium cladosporioides (Fresen.) de Vries extracts led to the isolation of four compounds, including cladosporin, 1; isocladosporin, 2; 5′-hydroxyasperentin, 3; ...and cladosporin-8-methyl ether, 4. An additional compound, 5′,6-diacetylcladosporin, 5, was synthesized by acetylation of compound 3. Compounds 1–5 were evaluated for antifungal activity against plant pathogens. Phomopsis viticola was the most sensitive fungus to the tested compounds. At 30 μM, compound 1 exhibited 92.7, 90.1, 95.4, and 79.9% growth inhibition against Colletotrichum acutatum, Colletotrichum fragariae, Colletotrichum gloeosporioides, and P. viticola, respectively. Compound 2 showed 50.4, 60.2, and 83.0% growth inhibition at 30 μM against Co. fragariae, Co. gloeosporioides, and P. viticola, respectively. Compounds 3 and 4 were isolated for the first time from Cl. cladosporioides. Moreover, the identification of essential structural features of the cladosporin nuclei has also been evaluated. These structures provide new templates for the potential treatment and management of plant diseases.
Endophytes, as crucial components of plant microbial communities, significantly contribute to enhancing the absorption of nutrients such as nitrogen and phosphorus by their hosts, promote plant ...growth, and degrade pathogenic fungal mycelia. In this study, an experiment was conducted in August 2022 to explore the growth-promoting potential of endophytic bacterial strains isolated from two medical plant species,
Thymus altaicus
and
Salvia deserta
, using a series of screening media. Plant samples of
Thymus altaicus
and
Salvia deserta
were collected from Zhaosu County and Habahe County in Xinjiang Uygur Autonomous Region, China, in July 2021. Additionally, the inhibitory effects of endophytic bacterial strains on the four pathogenic fungi (
Fusarium oxysporum, Fulvia fulva, Alternaria solani
, and
Valsa mali
) were determined through the plate confrontation method. A total of 80 endophytic bacterial strains were isolated from
Thymus altaicus
, while a total of 60 endophytic bacterial strains were isolated from
Salvia deserta
. The endophytic bacterial strains from both
Thymus altaicus
and
Salvia deserta
exhibited plant growth-promoting properties. Specifically, the strains of
Bacillus
sp. TR002,
Bacillus
sp. TR005,
Microbacterium
sp. TSB5, and
Rhodococcus
sp. TR013 demonstrated strong cellulase-producing activity, siderophore-producing activity, phosphate solubilization activity, and nitrogen-fixing activity, respectively. Out of 140 endophytic bacterial strains isolated from
Thymus altaicus
and
Salvia deserta
, 104 strains displayed anti-fungal activity against
Fulvia fulva, Alternaria solani, Fusarium oxysporum
, and
Valsa mali
. Furthermore, the strains of
Bacillus
sp. TR005,
Bacillus
sp. TS003, and
Bacillus
sp. TSB7 exhibited robust inhibition rates against all the four pathogenic fungi. In conclusion, the endophytic bacterial strains from
Thymus altaicus
and
Salvia deserta
possess both plant growth-promoting and anti-fungal properties, making them promising candidates for future development as growth-promoting agents and biocontrol tools for plant diseases.
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