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Abstract With the development of industry and modern manufacturing, nondegradable low-density polyethylene (LDPE) has been widely used, posing a rising environmental hazard to natural ecosystems and public health. In this study, we isolated a series of LDPE-degrading fungi from landfill sites and carried out LDPE degradation experiments by combining highly efficient degrading fungi in pairs. The results showed that the mixed microorganisms composed of Alternaria sp. CPEF-1 and Trametes sp. PE2F-4 (H-3 group) had a greater degradation effect on heat-treated LDPE (T-LDPE). After 30 days of inoculation with combination strain H-3, the weight loss rate of the T-LDPE film was approximately 154% higher than that of the untreated LDPE (U-LDPE) film, and the weight loss rate reached 0.66 ± 0.06%. Environmental scanning electron microscopy (ESEM) and Fourier transform infrared spectroscopy (FTIR) were used to further investigate the biodegradation impacts of T-LDPE, including the changes on the surface and depolymerization of the LDPE films during the fungal degradation process. Our findings revealed that the combined fungal treatment is more effective at degrading T-LDPE than the single strain treatment, and it is expected that properly altering the composition of the microbial community can help lessen the detrimental impact of plastics on the environment.

Numerous microorganisms, including bacteria and fungus, have been identified as capable of degrading rubber. Rubber biodegradation is still understudied due to its high stability and the lack of well-defined pathways and efficient enzymes involved in microorganism metabolism. However, rubber products manufacture and usage cause substantial environmental issues, and present physical-chemical methods involve dangerous chemical solvents, massive energy, and trash with health hazards. Eco-friendly solutions are required in this context, and biotechnological rubber treatment offers considerable promise. The structural and functional enzymes involved in poly (cis-1,4-isoprene) rubber and their cleavage mechanisms have been extensively studied. Similarly, novel bacterial strains capable of degrading polymers have been investigated. In contrast, relatively few studies have been conducted to establish natural rubber (NR) degrading bacterial consortia based on metagenomics, considering process optimization, cost effective approaches and larger scale experiments seeking practical and realistic applications. In light of the obstacles encountered during the constructing NR-degrading consortia, this study proposes the utilization of multi-omics tools to discern the underlying mechanisms and metabolites of rubber degradation, as well as associated enzymes and effective synthesized microbial consortia. In addition, the utilization of omics tool-based methods is suggested as a primary research direction for the development of synthesized microbial consortia in the future.

A free-living Bradyrhizobium strain isolated from a contaminated sediment sample collected at a water depth of 4 m from the Hongze Lake in China was characterized. Phylogenetic investigation of the 16S rRNA gene, concatenated housekeeping gene sequences, and phylogenomic analysis placed this strain in a lineage distinct from all previously described Bradyrhizobium species. The sequence similarities of the concatenated housekeeping genes support its distinctiveness with the type strains of the named species. The complete genome of strain S12-14-2 consists of a single chromosome of size 7.3M. The strain lacks both a symbiosis island and important nodulation genes. Based on the data presented here, the strain represents a new species, for which the name Bradyrhizobium roseus sp. nov. is proposed for the type strain S12-14-2T. Several functional differences between the isolate and other published genomes indicate that the genus Bradyrhizobium is extremely heterogeneous and has functions within the community, such as non-symbiotic nitrogen fixation. Functional denitrification and nitrogen fixation genes were identified on the genomes of strain S12-14-2T. Genes encoding proteins for sulfur oxidation, sulfonate transport, phosphonate degradation, and phosphonate production were also identified. Lastly, the B. roseus genome contained genes encoding ribulose 1,5-bisphosphate carboxylase/oxygenase, a trait that presumably enables autotrophic flexibility under varying environmental conditions. This study provides insights into the dynamics of a genome that could enhance our understanding of the metabolism and evolutionary characteristics of the genus Bradyrhizobium and a new genetic framework for future research.

Bacteria-related cancer immunotherapy, because of its mechanisms and useful applications in the induction of anti-tumor immunity, has gained substantial attention in recent decades. Bacteria can enable targeting of tumors, and specifically can colonize the core tumor area. Because they contain many pathogen-associated molecular patterns—which efficiently stimulate immune cells, even within microenvironments that suppress anti-tumor immunity—bacteria boost immunological recognition leading to the destruction of malignant cells. This Editorial highlights various bacteria with immunotherapeutic effects and their by-products used as immunotherapeutics.

Abstract Background Membrane lipid remodeling involves regulating the physiochemical modification of cellular membranes against abiotic stress or senescence, and it could be a trigger to increase neutral lipid content. In algae and higher plants, monogalactosyldiacylglycerol (MGDG) constitutes the highest proportion of total membrane lipids and is highly reduced as part of the membrane lipid remodeling response under several abiotic stresses. However, genetic regulation of MGDG synthesis and its influence on lipid synthesis has not been studied in microalgae. For development of an industrial microalgae strain showing high accumulation of triacylglycerol (TAG) by promoting membrane lipid remodeling, MGDG synthase 1 (MGD1) down-regulated mutant of Chlamydomonas reinhardtii (Cr-mgd1) was generated and evaluated for its suitability for biodiesel feedstock. Results The Cr-mgd1 showed a 65% decrease in CrMGD1 gene expression level, 22% reduction in MGDG content, and 1.39 and 5.40 times increase in diacylglyceryltrimethylhomoserines (DGTS) and TAG, respectively. The expression levels of most genes related to the decomposition of MGDG (plastid galactoglycerolipid degradation1) and TAG metabolism (diacylglycerol O-acyltransferase1, phospholipid:diacylglycerol acyltransferase, and major lipid droplet protein) were increased. The imbalance of DGDG/MGDG ratio in Cr-mgd1 caused reduced photosynthetic electron transport, resulting in less light energy utilization and increased reactive oxygen species levels. In addition, endoplasmic reticulum stress was induced by increased DGTS levels. Thus, accelerated TAG accumulation in Cr-mgd1 was stimulated by increased cellular stress as well as lipid remodeling. Under high light (HL) intensity (400 µmol photons/m2/s), TAG productivity in Cr-mgd1–HL (1.99 mg/L/d) was 2.71 times higher than that in wild type (WT–HL). Moreover, under both nitrogen starvation and high light intensity, the lipid (124.55 mg/L/d), TAG (20.03 mg/L/d), and maximum neutral lipid (56.13 mg/L/d) productivity were the highest. Conclusions By inducing lipid remodeling through the mgd1 gene expression regulation, the mutant not only showed high neutral lipid content but also reached the maximum neutral lipid productivity through cultivation under high light and nitrogen starvation conditions, thereby possessing improved biomass properties that are the most suitable for high quality biodiesel production. Thus, this mutant may help understand the role of MGD1 in lipid synthesis in Chlamydomonas and may be used to produce high amounts of TAG.

Numerous microorganisms and other invertebrates that are able to degrade polyethylene (PE) have been reported. However, studies on PE biodegradation are still limited due to its extreme stability and the lack of explicit insights into the mechanisms and efficient enzymes involved in its metabolism by microorganisms. In this review, current studies of PE biodegradation, including the fundamental stages, important microorganisms and enzymes, and functional microbial consortia, were examined. Considering the bottlenecks in the construction of PE-degrading consortia, a combination of top-down and bottom-up approaches is proposed to identify the mechanisms and metabolites of PE degradation, related enzymes, and efficient synthetic microbial consortia. In addition, the exploration of the plastisphere based on omics tools is proposed as a future principal research direction for the construction of synthetic microbial consortia for PE degradation. Combining chemical and biological upcycling processes for PE waste could be widely applied in various fields to promote a sustainable environment.

Low density polyethylene (LDPE) has been widely used commercially for decades; however, as a non-degradable material, its continuous accumulation has contributed to serious environmental issues. A fungal strain, Cladosporium sp. CPEF-6 exhibiting a significant growth advantage on MSM-LDPE (minimal salt medium), was isolated and selected for biodegradation analysis. LDPE biodegradation was analyzed by weight loss percent, change in pH during fungal growth, environmental scanning electron microscopy (ESEM), and Fourier transformed infrared spectroscopy (FTIR). Inoculation with the strain Cladosporium sp. CPEF-6 resulted in a 0.30 ± 0.06% decrease in the weight of untreated LDPE (U-LDPE). After heat treatment (T-LDPE), the weight loss of LDPE increased significantly and reached 0.43 ± 0.01% after 30 days of culture. The pH of the medium was measured during LDPE degradation to assess the environmental changes caused by enzymes and organic acids secreted by the fungus. The fungal degradation of LDPE sheets was characterized by ESEM analysis of topographical alterations, such as cracks, pits, voids, and roughness. FTIR analysis of U-LDPE and T-LDPE revealed the appearance of novel functional groups associated with hydrocarbon biodegradation as well as changes in the polymer carbon chain, confirming the depolymerization of LDPE. This is the first report demonstrating the capacity of Cladosporium sp. to degrade LDPE, with the expectation that this finding can be used to ameliorate the negative impact of plastics on the environment.

The strain designated as AN120528T was isolated from farmland soil in South Korea. This strain grows well on R2A medium at 28 °C. The cells are an off-white colour and have no hyphae. The phylogenetic analysis indicated that the strain is a member of the genus Shimazuella with a 98.11% similarity to Shimazuella alba KC615T and a 97.05% similarity to S. kribbensis KCTC 9933T, respectively. The strain AN120528T shares common chemotaxonomic features with the other two type strains in the genus. It has MK-9 (H4) and MK-10 (H4) as its predominant menaquinones. The major fatty acids are iso-C14:0, iso-C15:0, anteiso-C15:0 and iso-C16:0. Diphosphatidylglycerol (DPG), phosphatidylethanolamine (PE), phosphatidylglycerol (PG), lipids (L), and aminolipids (AL) were identified as the major cellular polar lipids. Analysis of the peptidoglycan showed the presence of meso-diaminopimelic acid. Whole-genome sequencing revealed that the genome of the strain is approximately 3.3 Mbp in size. The strain showed a 77.5% average nucleotide identity (ANI) with S. alba KC615T. The genomic DNA (gDNA) G + C content is 39.0%. Based on polyphasic taxonomy analysis, it is proposed that this strain, AN120528T, represents a novel species in the genus Shimazuella, designated as Shimazuella soli sp. nov. The type stain is AN120528T (=KCTC 39810T = DSM 103571T). Furthermore, shimazuellin I, a new 15-amino-acid peptide, was discovered in the AN120528T through genome mining; it has the features of a lasso peptide, containing eight amino acids (-G-Q-G-G-S-N-N-D-) that form a macrolactam ring and seven amino acids (-D-G-W-Y-H-S-K-) that form a tail.

The majority of terrestrial plants are symbiotic with arbuscular mycorrhizal fungi (AMF). Plants supply carbohydrates to microbes, whereas AMF provide plants with water and other necessary nutrients—most typically, phosphorus. Understanding the response of the AMF community structure to biogas slurry (BS) fertilization is of great significance for sustainable forest management. This study aimed to look into the effects of BS fertilization at different concentrations on AMF community structures in rhizospheric soil in poplar plantations. We found that different fertilization concentrations dramatically affected the diversity of AMF in the rhizospheric soil of the poplar plantations, and the treatment with a high BS concentration showed the highest Shannon diversity of AMF and OTU richness (Chao1). Further analyses revealed that Glomerales, as the predominant order, accounted for 36.2–42.7% of the AMF communities, and the relative abundance of Glomerales exhibited negligible changes with different BS fertilization concentrations, whereas the order Paraglomerales increased significantly in both the low- and high-concentration treatments in comparison with the control. Furthermore, the addition of BS drastically enhanced the relative abundance of the dominant genera, Glomus and Paraglomus. The application of BS could also distinguish the AMF community composition in the rhizospheric soil well. An RDA analysis indicated that the dominant genus Glomus was significantly positively correlated with nitrate reductase activity, while Paraglomus showed a significant positive correlation with available P. Overall, the findings suggest that adding BS fertilizer to poplar plantations can elevate the diversity of AMF communities in rhizospheric soil and the relative abundance of some critical genera that affect plant nutrient uptake.

Phosphorus is one of the main nutrients necessary for plant growth and development. Phosphorus-dissolving microorganisms may convert insoluble phosphorus in soil into available phosphorus that plants can easily absorb and utilize. In this study, four phosphorus-solubilizing fungi (L3, L4, L5, and L12) were isolated from the rhizosphere soil of a poplar plantation in Dongtai, Jiangsu Province, China. Phylogenetic analysis based on the internal transcribed spacer (ITS) and large subunit (LSU) of the ribosomal DNA sequences showed that the ITS and 28S sequences of isolates were the most similar to those of Mortierella. Morphological observation showed that most colonies grew in concentric circles and produced spores under different culture conditions. These results and further microscopic observations showed that these isolated fungi belonged to the genus Mortierella. Pikovskaya (PKO) medium, in which tricalcium phosphate was the sole phosphorus source, was used to screen strain L4 with the best phosphorus-solubilizing effect for further study. When the carbon source was glucose, the nitrogen source was ammonium chloride, the pH was 5, and the available phosphorus content was the highest. By exploring the possible mechanism of phosphorus release by phosphorus-solubilizing fungi, it was found that strain L4 produces several organic acids, such as oxalic acid, lactic acid, acetic acid, succinic acid, tartaric acid, malic acid, and citric acid. At 24 h, the alkaline phosphatase and acid phosphatase activities reached 154.72 mol/(L·h) and 120.99 mol/(L·h), respectively.

Lactobacillus, a genus of lactic acid bacteria, plays a crucial function in food production preservation, and probiotics. It is particularly important to develop new Lactobacillus strains with superior performance by gene editing. Currently, the identification of its functional genes and the mining of excellent functional genes mainly rely on the traditional gene homologous recombination technology. CRISPR/Cas9-based genome editing is a rapidly developing technology in recent years. It has been widely applied in mammalian cells, plants, yeast, and other eukaryotes, but less in prokaryotes, especially Lactobacillus. Compared with the traditional strain improvement methods, CRISPR/Cas9-based genome editing can greatly improve the accuracy of Lactobacillus target sites and achieve traceless genome modification. The strains obtained by this technology may even be more efficient than the traditional random mutation methods. This review examines the application and current issues of CRISPR/Cas9-based genome editing in Lactobacillus, as well as the development trend of CRISPR/Cas9-based genome editing in Lactobacillus. In addition, the fundamental mechanisms of CRISPR/Cas9-based genome editing are also presented and summarized.

A microcystin-degrading bacterial strain, Blastomonas fulva T2, was isolated from the culture of a microalgae Microcystis. The strain B. fulva T2 is Gram-stain-negative, non-motile, aerobic, non-spore-forming and phototrophic. The cells of B. fulva T2 are able to grow in ranges of temperature from 15 to 37 °C, with a pH of 6 to 8 and a salinity of 0 to 1% NaCl. Here, we sequenced the complete genome of B. fulva T2, aiming to better understand the evolutionary biology and the function of the genus Blastomonas at the molecular level. The complete genome of B. fulva T2 contained a circular chromosome (3,977,381 bp) with 64.3% GC content and a sizable plasmid (145.829 bp) with 60.7% GC content which comprises about 3.5% of the total genetic content. A total of 3842 coding genes, including 46 tRNAs and 6 rRNAs, were predicted in the genome. The genome contains genes for glycolysis, citric acid cycle, Entner–Doudoroff pathways, photoreaction center and bacteriochlorophylla synthesis. A 7.9 K gene cluster containing mlrA, mlrB, mlrC and mlrD1,2,3,4 of microcystin-degrading enzymes was identified. Notably, eight different efflux pumps categorized into RND, ABC and MFS types have been identified in the genome of strain T2. Our findings should provide new insights of the alternative reaction pathway as well as the enzymes which mediated the degradation of microcystin by bacteria, as well as the evolution, architectures, chemical mechanisms and physiological roles of the new bacterial multidrug efflux system.

Dimethyl sulfide (DMS) is an important component of the global sulfur cycle as it is the most abundant sulfur compound that is emitted via the ocean surface to the atmosphere. Dimethylsulfoniopropionate (DMSP), the precursor of DMS, is mainly produced by phytoplankton and is degraded by marine bacteria. To reveal the role of bacteria in the regulation of DMSP degradation and DMS production, mesocosm and field studies were performed in the Sanriku Coast on the Pacific Ocean in northeast Japan. The responsible bacteria for the transformation of DMSP to DMS and the assimilation of DMSP were monitored, and the genes encoding DMSP lyase (dddD and dddP) and DMSP demethylase (dmdA) were analyzed. The mesocosm study showed that the dmdA subclade D was the dominant DMSP degradation gene in the free-living (FL) and particle-associated (PA) fractions. The dddD gene was found in higher abundance than the dddP gene in all the tested samples. Most importantly, DMS concentration was positively correlated with the abundance of the dddD gene. These results indicated that bacteria possessing dmdA and dddD genes were the major contributors to the DMSP degradation and DMS production, respectively. The genes dmdA subclade D and dddP were abundant in the Tsugaru Warm (TW) Current, while the dmdA subclade C/2 and dddD genes were dominant in the Oyashio (OY) Current. Functional gene network analysis also showed that the DMSP degradation genes were divided into OY and TW Current-related modules, and genes sharing similar functions were clustered in the same module. Our data suggest that environmental fluctuations resulted in habitat filtering and niche partitioning of bacteria possessing DMSP degradation genes. Overall, our findings provide novel insights into the distribution and abundance of DMSP degradation genes in a coastal region with different water current systems.

The genus Gemmobacter grows phototrophically, aerobically, or anaerobically, and utilizes methylated amine. Here, we present two high-quality complete genomes of the strains con4 and con5T isolated from a culture of Anabaena. The strains possess sMMO (soluble methane monooxygenase)-oxidizing alkanes to carbon dioxide. Functional genes for methane-oxidation (prmAC, mimBD, adh, gfa, fdh) were identified. The genome of strain con5T contains nirB, nirK, nirQ, norB, norC, and norG genes involved in dissimilatory nitrate reduction. The presence of nitrite reductase gene (nirK) and the nitric-oxide reductase gene (norB) indicates that it could potentially use nitrite as an electron acceptor in anoxic environments. Taxonomic investigations were also performed on two strains through polyphasic methods, proposing two isolates as a novel species of the genus Gemmobacter. The findings obtained through the whole genome analyses provide genome-based evidence of complete oxidation of methane to carbon dioxide. This study provides a genetic blueprint of Gemmobacter fulva con5T and its biochemical characteristics, which help us to understand the evolutionary biology of the genus Gemmobacter.

Abstract Genome editing techniques are critical for manipulating genes not only to investigate their functions in biology but also to improve traits for genetic engineering in biotechnology. Genome editing has been greatly facilitated by engineered nucleases, dubbed molecular scissors, including zinc-finger nuclease (ZFN), TAL effector endonuclease (TALEN) and clustered regularly interspaced palindromic sequences (CRISPR)/Cas9. In particular, CRISPR/Cas9 has revolutionized genome editing fields with its simplicity, efficiency and accuracy compared to previous nucleases. CRISPR/Cas9-induced genome editing is being used in numerous organisms including microalgae. Microalgae have been subjected to extensive genetic and biological engineering due to their great potential as sustainable biofuel and chemical feedstocks. However, progress in microalgal engineering is slow mainly due to a lack of a proper transformation toolbox, and the same problem also applies to genome editing techniques. Given these problems, there are a few reports on successful genome editing in microalgae. It is, thus, time to consider the problems and solutions of genome editing in microalgae as well as further applications of this exciting technology for other scientific and engineering purposes.

To elucidate the interspecies connectivity between cyanobacteria and other bacteria (non-cyanobacteria) during cyanobacterial harmful algal blooms (cyanoHABs), samples were collected from the Nakdong River, Korea, from June 2016 to August 2017, and microbial recurrent association network (MRAN) analysis was performed to overcome the limitations of conventional network analysis. Microcystis blooms were tightly linked with Pseudanabaena in summer and were accompanied by significant changes in the non-cyanobacterial community composition (nCCC) compared to non-bloom period. Riverine bacterial communities could be clearly separated into modules that were involved in the formation, maintenance, and decomposition of cyanoHABs. Roseomonas and Herbaspirillum were directly linked with major cyanobacteria and assigned to connector and module hub in cyanoHABs-related modules, respectively. The functional profiles of the cyanoHABs-related modules suggested that nitrate reduction, aerobic ammonia oxidation, fermentation, and hydrocarbon degradation could be increased during the Microcystis bloom periods. In conclusion, MRAN analysis revealed that specific bacteria belonging to cyanoHABs-related module, including connectors and module hubs, appeared to contribute to the development and collapse of cyanoHABs. Therefore, to understand cyanoHABs, a modular microbial perspective may be more helpful than a single bacterial species perspective.

This genus contains both phototrophs and nonphototrophic members. Here, we present a high-quality complete genome of the strain CHu59-6-5T, isolated from a freshwater sediment. The circular chromosome (4.39 Mbp) of the strain CHu59-6-5T has 64.4% G+C content and contains 4240 genes, of which a total of 3918 genes (92.4%) were functionally assigned to the COG (clusters of orthologous groups) database. Functional genes for denitrification (narGHJI, nirK and qnor) were identified on the genomes of the strain CHu59-6-5T, except for N2O reductase (nos) genes for the final step of denitrification. Genes (soxBXAZY) for encoding sulfur oxidation proteins were identified, and the FSD and soxF genes encoding the monomeric flavoproteins which have sulfide dehydrogenase activities were also detected. Lastly, genes for the assembly of two different RND (resistance-nodulation division) type efflux systems and one ABC (ATP-binding cassette) type efflux system were identified in the Rhodoferax sediminis CHu59-6-5T. Phylogenetic analysis based on 16S rRNA sequences and Average Nucleotide Identities (ANI) support the idea that the strain CHu59-6-5T has a close relationship to the genus Rhodoferax. A polyphasic study was done to establish the taxonomic status of the strain CHu59-6-5T. Based on these data, we proposed that the isolate be classified to the genus Rhodoferax as Rhodoferax sediminis sp. nov. with isolate CHu59-6-5T.

The cloning and expression in Escherichia coli of a gene (bgpA) encoding a new ginsenoside-hydrolyzing [beta]-glucosidase from a novel bacterial strain, Terrabacter ginsenosidimutans sp. nov. Gsoil 3082, isolated from a ginseng farm in Korea is described. The studies have shown that BgpA is effective in the biotransformation of ginsenoside Rb1 to gypenoside (Gyp).

We characterized the complete sequence of the mitochondrial genome of the freshwater green algal strain YC001, known as 'Ettlia sp.', which is of great interest for biofuel production. The size of the mitogenome was 52,489 base pairs (bp), with 49.0% GC content. It consisted of 49 mitochondrial genes typical of the Chlorophyceae, including 16 protein-coding genes, 27 transfer RNA genes and six ribosomal RNA genes as well as three introns within cox1 (6832 bp), rnlA (1805 bp) and cob (1107 bp). We determined that YC001 is a species of Coelastrella on the basis of molecular phylogenetic analyses and microscopic observations. A unique feature of this mitogenome is the presence of three different types of inverted repeats between tmh and tml and between nadA and cox1 as well as the presence of orfl7555, and one additional copy of the trnM gene, all of which enable a comparison with an available sister taxon, Acutodesmus obliquus. [ABSTRACT FROM AUTHOR]

A new β-glucosidase from a novel strain of Terrabacter ginsenosidimutans (Gsoil 3082T) obtained from the soil of a ginseng farm was characterized, and the gene, bgpA (1,947 bp), was cloned in Escherichia coli. The enzyme catalyzed the conversion of ginsenoside Rb1 (3-0-[β-D-glucopyranosyl-(1-2)-β-D-glucopyranosyl]-20-O-[β-D- glucopyranosyl-(1-6)-β-D-glucopyranosyl]-20(S)-protopanaxadiol) to the more pharmacologically active rare ginsenosides gypenoside XVII (3-O-β-D-glucopyranosyl-20-O- [β-D-glucopyranosyl-(1-6)-β-D-glucopyranosyl] - 20(S)-protopanaxadiol), gypenoside LXXV (20-O- [β-D-glucopyranosyl.(1-6)-β-D-glucopyranosyl] -20(S)-pro-topanaxadiol), and C-K [20-O-(β-D-glucopyranosyl)-20(S)-protopanaxadiol]. A BLAST search of the bgpA sequence revealed significant homology to family 3 glycoside hydrolases. Expressed in E. coli, β-glucosidase had apparent Km values of 4.2 ± 0.8 and 0.14 ± 0.05 mM and Vmax values of 100.6 ± 17.1 and 329 ± 31 μmol ∙ min-1 ∙ mg of protein-1against p-nitrophenyl-β-D-glucopyranoside and Rb1, respectively. The enzyme catalyzed the hydrolysis of the two glucose moieties attached to the C-3 position of ginsenoside Rb1, and the outer glucose attached to the C-20 position at pH 7.0 and 37°C. These cleavages occurred in a defined order, with the outer glucose of C-3 cleaved first, followed by the inner glucose of C-3, and finally the outer glucose of C-20. These results indicated that BgpA selectively and sequentially converts ginsenoside Rb1 to the rare ginsenosides gypenoside XVII, gypenoside LXXV, and then C-K. Herein is the first report of the cloning and characterization of a novel ginsenoside-transforming β-glucosidase of the glycoside hydrolase family 3. [ABSTRACT FROM AUTHOR]