Disclosed herein is a UV mutagenesis produced new Streptomyces spororaveus strain SC263 that exhibits an increased thermostability of the antibiotic produced, which shows antibiotic activity against bacteria and fungi. Also provided are the antibiotic produced by SC263 and a composition thereof for treatment of bacterial and fungal infections. The antibiotic has a very high molecular weight, which is suitable for topical administration.

The present invention relates to a method for improving the heterologous synthesis of a polyketide by E. coli and use thereof. The yield of the polyketide heterologously synthesized by E. coli is significantly increased by attenuating the expression of seventy-two genes, such as sucC and talB, in a host strain, wherein the highest yield increase rate can reach 60% or more. Currently, erythromycin is the most clear model compound in the study on the biosynthesis of polyketids. The production strain of the present invention enables massive accumulation of 6-deoxyerythronolide (6-dEB), an erythromycin precursor, in the fermentation process, laying the foundation for the industrial production of the heterologous synthesis of erythromycin by E. coli.

The present invention is directed to methods and compositions for increasing a growth characteristic of a plant, increasing nutrient use efficiency of a plant, or improving a plant's ability to overcome biotic or abiotic stress comprising applying a composition comprising a fungal mycelia extract comprising piperidine and/or an analogue thereof (e.g., 6-oxopiperidine-2-carboxylic acid) and/or a salt thereof (e.g., 6-oxopiperidine-2-carboxylate), or any combination thereof to a plant, plant part, or to a propagation material of the plant.

A novel PSL family prenyltransferase has relaxed substrate specificity, which can use a variety of cyclic dipeptides and prenyl donors as substrates to produce various terpenylated diketopiperazines. An amino acid sequence of the prenyltransferase is SEQ ID NO:1. An application of the prenyltransferase is transferring different prenyl groups to Trp-containing cyclic dipeptides. The prenyltransferase catalyzes the formation of terpenylated diketopiperazines by assembling prenyl groups onto cyclic di peptides, which provides a new strategy for drug development of diketopiperazines.

The present invention relates to a DoxA protein mutant having an amino acid sequence set forth in SEQ ID No. 16, and coding gene thereof. The protein mutant or the coding gene thereof can be used for producing epirubicin. The present invention further relates to a Streptomyces capable of efficiently expressing epirubicin, which is constructed by replacing the dnmV gene of a starting Streptomyces in situ with the avrE gene and mutating the doxA gene of the starting Streptomyces into a gene encoding the protein set forth in SEQ ID No. 16. The fermentation broth of this Streptomyces has an epirubicin potency of up to 102.0 g/ml.

The application belongs to the field of biotechnology and microbiology, in particular to a strain of Streptomyces roseoverticillatus (Sr-63) which antagonizes the Rice Bacterial Blight and its application in the prevention and treatment of plant diseases. The application discloses a strain of S. roseoverticillatus (Sr-63) with the accession number CCTCC No.: M 2019261. It is also disclosed the application of the S. roseoverticillatus (Sr-63): used for controlling Rice Bacterial Blight.

This disclosure describes compositions and methods for enhanced production of enduracidin in genetically engineered strains of Streptomyces fungicidicus. In particular, the present disclosure describes the genetic manipulation of regulatory genes orf24 and orf18 associated with the enduracidin (enramycin) biosynthesis gene cluster from Streptomyces fungicidicus to generate vector constructs and recombinant strains producing greater yields of enduracidin.

The present invention provides Streptomyces coelicolor strain A3(2)_M22-2C43 obtained by inducing a point mutation in the base sequence of the DagB gene in a wild-type Streptomyces coelicolor strain A3(2) by UV radiation. Since the Streptomyces coelicolor strain A3(2)_M22-2C43 according to the present invention expresses a DagB mutant enzyme expressing little or no DagB beta-agarase or exhibiting little or no beta-agarase activity, there is no need for separate isolation and purification of DagA enzymes from culture fluid, and the culture fluid of the Streptomyces coelicolor strain A3(2)_M22-2C43 or supernatant thereof may be used to produce, from agar or agarose, neoagarose oligosaccharides with a higher content of neoagarotetraose or neoagarohexaose than that of neoagarobiose.

The present invention relates to a strain for producing chitinase and application thereof. The class of the strain is named Streptomyces diastaticus CS1801 and the preservation number thereof is CCTCC NO: M2018263. The Streptomyces diastaticus CS1801 of the present invention is derived from naturally fermented prawn paste. By fermentation of prawns, the enzyme activity of the chitosan is as high as 57.3 U/L and the content of chitooligosaccharides is 0.58 mol/L. The present invention provides a new method for producing chitooligosaccharides and has a good application prospect.

The present invention relates to the analysis of complex single cell sequencing libraries. Disclosed are methods for enrichment of library members based on the presence of cell-of origin barcodes to identify and concentrate DNA that is relevant to interesting cells or components that would be expensive or difficult to study otherwise. Also, disclosed are methods of capturing cDNA library molecules by use of CRISPR systems, hybridization or PCR. The present invention allows for identifying the properties of rare cells in single cell RNA-seq data and accurately profile them through clustering approaches. Further information on transcript abundances from subpopulations of single cells can be analyzed at a lower sequencing effort. The methods also allow for linking TCR alpha and beta chains at the single cell level.