Journal of Industrial Microbiology & Biotechnology最新文献

Phosphopantetheinyl transferases (PPTases) play an essential role in primary and secondary metabolism. These enzymes facilitate the posttranslational activation of acyl carrier proteins (ACPs) central to the biosynthesis of fatty acids and polyketides. Modulation of ACP-PPTase interactions is a promising approach to both increase access to desired molecular outputs and disrupt mechanisms associated with disease progression. However, such an approach requires understanding the molecular principles that govern ACP-PPTase interactions across diverse synthases. Through a multiyear, course-based undergraduate research experience (CURE), 17 ACPs representing a range of putative type II polyketide synthases, from actinobacterial and nonactinobacterial phyla, were evaluated as substrates for three PPTases (AcpS, Sfp, and vulPPT). The observed PPTase compatibility, sequence-level analyses, and predictive structural modeling suggest that ACP selectivity is driven by amino acids surrounding the conserved, modified serine on the ACP. We propose that vulPPT and Sfp interactions with ACPs are driven primarily by hydrophobic contacts, whereas AcpS may favor ACPs that exhibit high net-negative charge density, as well as a broad electronegative surface distribution. Furthermore, we report a plausible, hitherto unreported hydrophobic interaction between vulPPT and a conserved ACP crease upstream of the invariant serine, which may facilitate docking. This work provides a catalog of compatible and incompatible ACP-PPTase partnerships, highlighting specific regions on the ACP and/or PPTase that show promise for future strategic engineering and inhibitor development efforts. One-Sentence Summary: Seventeen acyl carrier proteins from diverse type II polyketide synthases were evaluated for their compatibility with three phosphopantetheinyl transferases; results, along with sequence level-analyses and predictive structural modeling, reveal specific regions that can guide future strategic engineering efforts.

In the last decade, the global warming and plastic pollution issue have driven research on developing a more sustainable platform for chemicals production from alternative feedstocks. Ethylene glycol (EG), a monomer of polyethylene terephthalate (PET) plastic, has a potential to become a renewable substrate for microbial production of value-added chemicals. This study presents a biotransformation platform using Corynebacterium glutamicum to produce glycolic acid (GA) from EG. C. glutamicum was engineered to express a heterologous EG oxidation pathway. Subsequent promoter engineering yielded strain FA4, producing 10.6 g/L GA from EG in 48 h. Implementation of a two-stage biotransformation strategy using resting cells further enhanced the GA production, reaching a cumulative GA titer of 98.8 g/L after a 72-h production. Finally, applying this platform to a simulated EG mixture from PET-degradation achieved a cumulative GA titer of 67.3 g/L over 72 h, highlighting the potential for valorizing plastic waste through this biotransformation platform. These findings establish C. glutamicum as an efficient biotransformation chassis for sustainable GA production from EG and offer a promising route for PET waste valorization into value-added chemicals. One Sentence Summary: High yield production of GA from EG.

Glycocins are a growing family of ribosomally synthesized and posttranslationally modified peptides (RiPPs) that are O- and/or S-glycosylated. Using a sequence similarity network of putative glycosyltransferases, the thg biosynthetic gene cluster (BGC) was identified in the genome of Thermoanaerobacterium thermosaccharolyticum. Heterologous expression in Escherichia coli showed that the glycosyltransferase (ThgS) encoded in the BGC adds N-acetyl-glucosamine (GlcNAc) to Ser and Cys residues of ThgA. The peptide derived from ThgA, which we name thermoglycocin, was structurally characterized and shown to resemble glycocin F. In addition to two nested disulfide bonds also present in glycocin F, thermoglycocin contains a third disulfide bond creating a C-terminal loop. Unexpectedly, ThgA lacks the common double glycine motif for leader peptide removal by a C39-peptidase. Based on AlphaFold3 modeling, we postulated that cleavage between the leader and core peptide would occur instead at a GK motif, which was experimentally confirmed for an orthologous BGC from Ornithinibacillus bavariensis. Its structurally similar product termed orniglycocin was also produced in E. coli and carries two GlcNAc moieties on two Cys residues. The C39 peptidase domain of the peptidase-containing ATP-binding cassette transporter (PCAT) from this BGC removed the leader peptide after a Gly-Lys motif and the orniglycocin so produced demonstrated antimicrobial activity. This study adds to the small number of characterized glycocins, employs AlphaFold3 to predict the leader peptide cleavage site, and suggests a common naming convention similar to that established for lanthipeptides. One-Sentence Summary: Thermoglycocin from Thermoanaerobacterium thermosaccharolyticum and orniglycocin from Ornithinibacillus bavariensis were produced heterologously in E. coli, shown to contain three disulfide bonds and two GlcNAcylations, and were released by a unique C39 protease that cleaves at a Gly-Lys sequence.

Nucleoside deoxyribosyl transferase (NDT) is an enzyme that catalyzes the transfer of purine and pyrimidine bases between 2'-deoxyribonucleosides and is widely used for synthesizing nucleoside analogs in various biotechnological applications. While NDT exhibits high activity toward natural nucleosides, its activity toward unnatural nucleoside analogs is significantly lower. Previously, the NDT mutant named fNDT(L59Q) was identified displaying 4.4-fold higher activity toward 2'-fluoro-2'-deoxyuridine (2FDU). In this study, molecular evolution strategies using error-prone PCR were employed to further generate mutant enzymes with enhanced activity toward 2FDU. After two rounds of mutational screening, two mutant clones that exhibited high activity against 2FDU were identified as fNDT-i1 (V52A) and fNDT-i2 (L28I), respectively. A double mutant, fNDT-i4, was subsequently constructed by combining the V52A and L28I mutations. Whole-cell-based activity measurements showed that fNDT-i4 exhibited 4.0- and 20.6-fold higher activity at 40°C and 50°C, respectively, compared to the wild-type NDT. The detailed characterization of the purified enzymes conducted under various conditions, including temperature, pH, thermal stability, and enzyme kinetics experiments, showed that fNDT-i1 and fNDT-i4 exhibited 3.1- and 3.7-fold higher catalytic efficiency, respectively than wild-type NDT. The L59Q mutation was identified as a key factor in improving the thermal stability, whereas the V52A and L28I mutations were critical for improving substrate affinity and reaction efficiency. These findings provide the potential of fNDT-i1 and fNDT-i4 as highly efficient biocatalysts for developing industrially relevant nucleoside analog synthesis.

One-sentence summary: The nucleoside deoxyribosyl transferase mutant were engineered to enhance biological activity and physical resistance for production of fluorinated deoxynucleoside as a raw material of oligonucleotide therapeutics.

More than one billion tons of chaff waste are generated globally every year, but traditional recycling methods face the dual challenges of inefficiency and environmental risks, to solve this problem, this study innovatively achieves the dual functions of lignocellulosic synergistic degradation and plant promotion by constructing synthetic microbial communities. Firstly, a cellulose-degrading bacterium cmk-7 (Chromobacterium violaceum) was screened from soil based on Congo red staining method, and the maximum values of CMCase enzyme activity and FPase enzyme activity were 289.12 and 332.95 U/mL, respectively, and the culture conditions of cellulose-degrading bacteria were optimized by single factor test and response surface experiment, and its production intensity was increased by 2.43 times, respectively. Subsequently, cellulose-degrading bacteria were mixed with nitrogen-fixing bacterium Enterobacter tabaci lmy-3-2 in a 1:1 ratio to prepare a composite bacterial agent A7 to treat rice husks for potting experiments and seedling experiments. After 80 days of fermentation, the surface structure of rice husk, the soil microbial community structure was significantly reconstructed, and the ratio of carbon and nitrogen content in the soil was changed, and the plant height growth of the compound agent A7 treatment group increased by 96.5% and 193.9%, respectively, compared with the Sterile water treatment and nitrogen-fixing single bacteria treatment group, which effectively promoted the growth of buckwheat seedlings. In this study, the triple effect coupling of "solid waste degradation-soil improvement-crop growth" was successfully realized, and a mass-produced microbiome solution was provided for the agricultural circular economy, with broad application prospects. One-Sentence Summary: The cellulose-degrading bacterium cmk-7 was screened and optimized to make a compound microbial agent with nitrogen-fixing bacterium lmy-3-2, which could promote chaff degradation and crop growth.

In this review, we focus on how purple non-sulfur bacteria can be leveraged for sustainable bioproduction to support the circular economy. We discuss the state of the field with respect to the use of purple bacteria for energy production, their role in wastewater treatment, as a fertilizer, and as a chassis for bioplastic production. We explore their ability to serve as single-cell protein and production platforms for fine chemicals from waste materials. We also introduce more Avant-Garde technologies that leverage the unique metabolisms of purple bacteria, including microbial electrosynthesis and co-culture. These technologies will be pivotal in our efforts to mitigate climate change and circularize the economy in the next two decades.

One-sentence summary: Purple non-sulfur bacteria are utilized for a range of biotechnological applications, including the production of bio-energy, single cell protein, fertilizer, bioplastics, fine chemicals, in wastewater treatment and in novel applications like co-cultures and microbial electrosynthesis.

Since ancient times, humans have harnessed the vast metabolic abilities of fungi to produce food, beverages, and medicines. Biotechnology and genetic engineering have opened new avenues to tailor and enhance these abilities, transforming fungi into powerful industrial workhorses. In this minireview, we focus on the biotechnological potential of Agaricomycetes, a class of basidiomycete fungi that includes the so-called 'true' mushrooms. Although many species are widely used in the food sector, their broader potential in biotechnology remains largely untapped. These fungi naturally produce a diverse array of metabolites with promising applications across various industries. Here, we highlight their ability to synthesize a wide range of terpenoids, many unique to this taxon, and we present recent advancements in genomics and genetic engineering tools developed for Agaricomycetes. We anticipate that continued progress in tailored genetic engineering tools and improved cultivation technologies will facilitate the establishment of these fungi as robust cell factories for producing valuable terpenoids, with significant contributions to the food, biotech, and pharmaceutical sectors. One-Sentence Summary: This minireview highlights the potential of mushroom-forming fungi to be engineered into cell factories for producing terpenoids-valuable compounds with diverse applications in food, medicine, and biotechnology.

Cordyceps, a genus of Ascomycetes, represents a group of fungi that has attracted considerable attention from both the scientific community and practitioners of traditional medicine. Extensive research has established that Cordyceps exhibits various health-promoting properties, including antioxidant activity and enhanced liver function. Solid-state fermentation (SSF) is recognized as an effective method for cultivating microorganisms on solid substrates. Various optimization strategies for the medium have been employed to improve the production of high-quality bioactive substances. Most research has focused on combining Cordyceps fungi with diverse substrates, including grains, beans, herbal plants, fruits, etc. We explored the potential of these combinations in SSF, highlighting promising methods to increase mycochemical and metabolite yields from Cordyceps fungi, which hold broad application prospects, and the effects of antioxidants and related liver function. This review offers critical insights into effectively incorporating fungi and diverse materials within fermentation processes relevant to the nutritional, pharmacological, and biotechnological sectors. One-Sentence Summary: This review explores the potential of solid-state fermentation (SSF) to enhance the production of bioactive compounds from Cordyceps fungi using various substrates, highlighting its antioxidant and liver health benefits, and providing insights for applications in nutrition, pharmacology, and related industries.

The use of the endophytic fungus Serendipita indica has rapidly increased due to its wide range of host species, ability to foster plant-growth, and ability to confer tolerance to a number of stresses. However, its industrial-scale production is still in its infancy due to its low-biomass yield and prolonged cultivation time. Thus far, Hill-Kafer medium has traditionally been used for S. indica cultivation, resulting in lower yields and excessively long incubation times. Here, we adopted a simple insoluble carbon and phosphate input medium for rapidly generating high biomass. We developed and optimized the SIF1 medium, achieving maximum biomass production (424.5 ± 1.9 g/L), significantly outperforming Hill-Kafer medium. Statistical optimization of SIF1 identified optimal levels (15 g/L oats, 7.5 g/L tricalcium phosphate, 95-hr incubation). Validated results in the laboratory (FUS-10 L: 484.4 ± 4.7), pilot (300 L: 496.5 ± 7 g/L), and industrial (3000L: 492.4 ± 7.1 g/L) bioreactors proved the efficacy of SIF1. Compared to Hill-Kafer (54.8 ± 3.7 g/L), SIF1 showed nine-fold higher biomass productivity and reduced cultivation time by approximately 6 days. Based on our findings, it appears that SF1 will be a highly efficient medium for producing S. indica on an industrial scale and expanding its use.

One-sentence summary: This study presents a rapid industrial production strategy for the beneficial fungus Serendipita indica, providing a scalable solution for wider applications and contributing to global food security and environmental sustainability.

Microbial isolates from sugar crop processing facilities were tested for sensitivity to several industrial antimicrobial agents to determine optimal dosing. Hydritreat 2216 showed broad-spectrum activity against all bacterial isolates as well as Saccharomyces cerevisiae. Sodium hypochlorite showed broad-spectrum activity against all isolates, but at much higher effective concentrations. Hops BetaStab XL was effective against Gram-positive isolates. Magna Cide D minimum inhibitory concentration was lowest for S. cerevisiae and Zymomonas mobilis but was less effective against Gram-positive bacterial strains. Based on laboratory experiments, factory losses of sucrose from a single microbial species in the absence of antimicrobials could range from 0.13 to 0.52 kg of sucrose per tonne of cane. Additional improvements in sugar yield are anticipated from agents with broad-spectrum activity. A cost analysis was conducted considering sucrose savings due to antimicrobial application to provide estimates for break-even costs, which ranged from approximately $0.50 to $2.00/L for a given antimicrobial agent.

One-sentence summary: Application of antimicrobial agents at minimal inhibitory doses for microbes results in optimal inhibition of microbial growth and sucrose consumption.