Development and Characterization of a Tunable Metal-Organic Framework (MOF) for the Synthesis of a Rare Sugar D-Tagatose.

D-tagatose is a valuable rare sugar with potential health benefits such as antiobesity, low-calorie, prebiotic, and anticancer. However, its production is mainly depending on chemical or enzymatic catalysis. Herein, a cobalt-based metal-organic framework (MOF) was developed at room temperature in an aqueous system using a self-assembly method. The L-arabinose isomerase (L-AI) was immobilized into this unique MOF by an in situ encapsulation process. The morphology and structural aspects of the MOF preparations were characterized by different analytical techniques such as scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), confocal laser scanning microscopy (CLSM), Fourier transform infrared spectroscopy (FT-IR), and X-Ray diffraction (XRD). Moreover, thermogravimetric analysis (TGA) suggested the high thermal stability of the L-AI@MOF. Significantly, the immobilized catalyst exhibited enhanced catalytic efficiency (kcat/Km) of 3.22 mM-1 s-1 and improved turnover number (kcat) of 57.32 s-1. The L-AI@MOF efficiently catalyzes the synthesis of D-tagatose from D-galactose up to the equilibrium level (~ 50%) of isomerization in heterogeneous catalysis. Interestingly, L-AI@MOF was found stable and reusable for more than five cycles without the requirement of additional metal ions during catalysis. Thus, L-AI stabilized in the MOF system demonstrated a higher catalytic activity and potential guidance for the sustainable synthesis of rare sugar D-tagatose.

Smart proteins as a new paradigm for meeting dietary protein sufficiency of India: a critical review on the safety and sustainability of different protein sources.

India, a global leader in agriculture, faces sustainability challenges in feeding its population. Although primarily a vegetarian population, the consumption of animal derived proteins has tremendously increased in recent years. Excessive dependency on animal proteins is not environmentally sustainable, necessitating the identification of alternative smart proteins. Smart proteins are environmentally benign and mimic the properties of animal proteins (dairy, egg and meat) and are derived from plant proteins, microbial fermentation, insects and cell culture meat (CCM) processes. This review critically evaluates the technological, safety, and sustainability challenges involved in production of smart proteins and their consumer acceptance from Indian context. Under current circumstances, plant-based proteins are most favorable; however, limited land availability and impending climate change makes them unsustainable in the long run. CCM is unaffordable with high input costs limiting its commercialization in near future. Microbial-derived proteins could be the most sustainable option for future owing to higher productivity and ability to grow on low-cost substrates. A circular economy approach integrating agri-horti waste valorization and C1 substrate synthesis with microbial biomass production offer economic viability. Considering the use of novel additives and processing techniques, evaluation of safety, allergenicity, and bioavailability of smart protein products is necessary before large-scale adoption.

Fermenter scale production of recombinant beta-mannanase by E. coli BL21 cells under microaerobic environment.

Aim of the study was to optimize and produce beta-mannanase at fermenter scale by using cheaper minimal media. Increased production of beta-mannanase from Microbacterium camelliasinensis CIAB417 was achieved by heterologous expression in E. coli BL21 (DE3). The scale-up production of beta-mannanase was optimized from shake flask to 5-L fermenter. The cost-effective minimal media (M9+e) without any vitamins was found to be most effective and optimized for culturing the cells. The same media displayed no significant fluctuation in the pH while culturing the cells for the production of beta-mannanase both at shake flask and fermenter level. Additionally, E. coli cells were able to produce similar amount of dry cell weight and recombinant beta-mannanase both in the presence of micro and macro-oxygen environment. The optimized media was demonstrated to show no significant drop in pH throughout the recombinant protein production process. In one litre medium, 2.0314 g dry weight of E. coli cells yielded 1.8 g of purified recombinant beta-mannanase. The purified enzyme was lyophilized and demonstrated to hydrolyse locust bean gum to release mannooligosaccharides.

Recent advances in 3D bioprinting for cancer research: From precision models to personalized therapies.

Cancer remains one of the most devastating diseases, necessitating innovative and precise therapeutic solutions. The emergence of 3D bioprinting has revolutionized the platform of cancer therapy by offering bespoke solutions for drug screening, tumor modeling, and personalized medicine. The utilization of 3D bioprinting enables the fabrication of complex tumor models that closely mimic the in vivo microenvironment, facilitating more accurate drug testing and personalized treatment strategies. Moreover, 3D bioprinting also provides a platform for the development of implantable scaffolds as a therapeutic solution to cancer. In this review, we highlight the application of 3D bioprinting for cancer therapy along with current advancements in cancer 3D model development with recent case studies.

Structural and functional insights of a cold-adaptive ß-glucosidase with very high glucose tolerance from Microbacterium sp. CIAB417.

A gene glu1 (WP_243232135.1) coding for ß-glucosidase from the genome of Microbacterium sp. CIAB417 was characterized for its cold adaptive nature and tolerance to high levels of glucose and ethanol. The phylogenetic analysis suggested the close association of glu1 with a similar gene from a mesophilic bacterium Microbacterium indicum. The purified recombinant GLU1 displayed its optimal activity and stability at pH 5 and temperature 30á´¼C. Additionally, the presence of L3 loop in GLU1 suggested its cold adaptive nature. The glucose tolerant Gate keeper residues (Leu 174 & Trp 169) with a distance of ∼ 6.953 Å between them was also predicted in GLU1. The GLU1 enzyme showed ≥ 95% and ≥ 40% relative activity in the presence of 5 M glucose and 20% ethanol. The Vmax, Km, and Kcat values of GLU1 for cellobiose substrate were observed to be 45.22 U/mg, 3.5 mM, and 41.0157 s-1, respectively. The GLU1 was found to be highly efficient in hydrolysis of celloologosaccharides (C2-C5), lactose and safranal picrocrocin into glucose. Hence, cold adaptive GLU1 with very high glucose and ethanol tolerance could be very useful in bio-refinery, dairy, and flavor industries.

Transcriptome analysis of ovules offers early developmental clues after fertilization in Cicer arietinum L.

Chickpea (Cicer arietinum L.) seeds are valued for their nutritional scores and limited information on the molecular mechanisms of chickpea fertilization and seed development is available. In the current work, comparative transcriptome analysis was performed on two different stages of chickpea ovules (pre- and post-fertilization) to identify key regulatory transcripts. Two-staged transcriptome sequencing was generated and over 208 million reads were mapped to quantify transcript abundance during fertilization events. Mapping to the reference genome showed that the majority (92.88%) of high-quality Illumina reads were aligned to the chickpea genome. Reference-guided genome and transcriptome assembly yielded a total of 28,783 genes. Of these, 3399 genes were differentially expressed after the fertilization event. These involve upregulated genes including a protease-like secreted in CO(2) response (LOC101500970), amino acid permease 4-like (LOC101506539), and downregulated genes MYB-related protein 305-like (LOC101493897), receptor like protein 29 (LOC101491695). WGCNA analysis and pairwise comparison of datasets, successfully constructed four co-expression modules. Transcription factor families including bHLH, MYB, MYB-related, C2H2 zinc finger, ERF, WRKY and NAC transcription factor were also found to be activated after fertilization. Activation of these genes and transcription factors results in the accumulation of carbohydrates and proteins by enhancing their trafficking and biosynthesis. Total 17 differentially expressed genes, were randomly selected for qRT-PCR for validation of transcriptome analysis and showed statistically significant correlations with the transcriptome data. Our findings provide insights into the regulatory mechanisms underlying changes in fertilized chickpea ovules. This work may come closer to a comprehensive understanding of the mechanisms that initiate developmental events in chickpea seeds after fertilization. Supplementary Information: The online version contains supplementary material available at 10.1007/s13205-023-03599-8.

CRISPR-Cas for genome editing: Classification, mechanism, designing and applications.

Clustered regularly interspersed short pallindromic repeats (CRISPR) and CRISPR associated proteins (Cas) system (CRISPR-Cas) came into light as prokaryotic defence mechanism for adaptive immune response. CRISPR-Cas works by integrating short sequences of the target genome (spacers) into the CRISPR locus. The locus containing spacers interspersed repeats is further expressed into small guide CRISPR RNA (crRNA) which is then deployed by the Cas proteins to evade the target genome. Based on the Cas proteins CRISPR-Cas is classified according to polythetic system of classification. The characteristic of the CRISPR-Cas9 system to target DNA sequences using programmable RNAs has opened new arenas due to which today CRISPR-Cas has evolved as cutting end technique in the field of genome editing. Here, we discuss about the evolution of CRISPR, its classification and various Cas systems including the designing and molecular mechanism of CRISPR-Cas. Applications of CRISPR-Cas as a genome editing tools are also highlighted in the areas such as agriculture, and anticancer therapy. Briefly discuss the role of CRISPR and its Cas systems in the diagnosis of COVID-19 and its possible preventive measures. The challenges in existing CRISP-Cas technologies and their potential solutions are also discussed briefly.

Immobilization of L-ribose isomerase on the surface of activated mesoporous MCM41 and SBA15 for the synthesis of L-ribose.

A hexagonal mesoporous molecular sieve-like structure of MCM41 and SBA15 with a large surface area was used to immobilize protein L-ribose isomerase (L-RI) through covalent linkages. The amino group of APTES functionalized nanosilica support MCM41 and SBA15 interacted with glutaraldehyde to promote bidentate linkage and on other side with amino group of enzyme. The use of mesoporous silica matrix for immobilization was observed to conserve the distinctive properties of the protein. The various operational conditions optimized for covalent conjugation of protein with the silica support were found to be dependent on enzyme support ratio, immobilization temperature and time. The immobilization yield of L-RI on MCM41 and SBA15 was achieved to be 60 % (600 mg enzyme /g matrix) and 45 % (450 mg enzyme/g matrix), respectively under the optimized conditions. The immobilized biocatalyst was characterized by various analytical techniques like HR-TEM, EDS, FTIR, TGA and BET. Effects of different experimental conditions were optimized to study enzyme kinetics, pH, temperature, bioconversion, reusability, metal ion effect and storage stability. The biocatalytic efficiency (kcat/Km) was increased by 1.2 fold on immobilization with the catalytic activity of 39.64 IU. Increase in the catalytic efficiency after immobilization could be due to the suitable orientation of enzyme active site and improved accessibility for substrate binding. The immobilization of L-RI on mesoporous silica support could improve the biocatalytic activity, storage stability and reusability. The immobilized biocatalyst was found to be reusable for more than 4 cycles retaining more than 50 % of catalytic activity and promoting the synthesis of a rare sugar L-ribose from L-ribulose with a conversion yield of 22 % in 2 h time.

Robust nano-enzyme conjugates for the sustainable synthesis of a rare sugar D-tagatose.

Aim of present study was to develop biological catalysts of L-arabinose isomerase (L-AI) by immobilizing on four different supports such as multiwalled carbon nanotube (MWCNT), graphene oxide (GOx), Santa Barbara Amorphous (SBA-15) and mobile composite matter (MCM-41). Also, comparative analysis of the developed catalysts was performed to evolve the best in terms of transformation efficiency for D-tagatose production. The developed nano-enzyme conjugates (NECs) were characterized using the high resolution transmission electron microscopy (HR-TEM) and elemental analysis was performed by energy dispersive X-ray spectroscopy (EDS). The functional groups were investigated by Fourier transform infra red spectroscopy. Also, the thermo gravimetric analysis (TGA) was employed to plot a thermal degradation weight loss profile of NECs. The conjugated L-AI with MWCNT and GOx were found to be more promising immobilized catalysts due to their ability to provide more surface area. Conversion of D-Galactose to D-Tagatose at moderate temperature and pH was observed to attain the equilibrium level of transformation (~50%). On the contrary, NECs prepared using SBA-15 and MCM-41 as support matrix were unable to reach the equilibrium level of conversion. Additionally, the developed NECs were suitable for reuse in multiple batch cycles. Thus, promising nanotechnology coupled with biocatalysis made the transformation of D-Galactose into D-tagatose more economically sustainable.

Metal-based micro-composite of L-arabinose isomerase and L-ribose isomerase for the sustainable synthesis of L-ribose and D-talose.

The biocatalysts are broadly explored in the biological transformation processes. The enzyme cascade catalysis involves various catalytic activities in a sequential process to produce the desired product including the formation of reaction intermediates. Enzyme immobilization is a method in which enzymes are confined within a support or matrix either physically or chemically to enhance their relative stability and catalytic activity in the enzyme cascade catalysis. In view of this, L-arabinose isomerase (L-AI) and L-ribose isomerase (L-RI) were immobilized on zeolite based metal framework as a micro-composite construct (DEMC@L-AI+L-RI) using linker, and metal ions. Such immobilization could be of great significance and provide several advantages like mesoporous surface for enzyme adsorption, desirable functionality in the production of products in enzyme cascade reaction, high storage stability and enhanced recyclability. The developed DEMC@L-AI+L-RI was characterized using SEM, FTIR, CLSM and TGA. The immobilization yield was 32% and loading of enzyme was 22% on the surface of micro-composite. The DEMC@L-AI+L-RI showed relatively stable catalytic activity at pH 5-6 and temperature 40 °C. The catalytic efficiency (kcat/Km) of both the enzymes was increased by 1.5-fold after immobilization. With the immobilized biocatalyst, bioconversion of L-arabinose to L-ribose was 22.6% and D-galactose to D-talose was 15.2%. The reusability of developed biocatalyst for more than six cycles was observed for more than 50% yield of the sugars. The conversion of biomass sugars from beetroot and onion waste residues was 20% and 14% to produce ribose and talose, respectively.

Genome sequencing of a novel Microbacterium camelliasinensis CIAB417 identified potential mannan hydrolysing enzymes.

Here, whole genome sequencing of Microbacterium sp. CIAB417 was conducted to determine its novelty at species level and identification of genes encoding for enzymes for mannan degradation. The draft genome was predicted to have 6.53 mbp length represented by 41 contigs and 6078 genes. However, only 82.35% genes were allocated for their functions. The whole genome phylogeny, ANI score (78.84%), GGDC (genome to genome distance calculations) show probability (DDH ≥ 70%) equal to 0% and difference in advanced biochemical properties among closely predicted species. The Microbacterium sp. CIAB417 was stipulated to be novel at species level. Isolate was named as Microbacterium camelliasinensis CIAB417 (accession no JAHZUT000000000) based on its isolation from a tea garden soil. Genome was predicted for three novel mannanase coding genes man1 (MZ702740), man2 (MZ702741), and man3 (MZ702737) that belong to the GH5 and GH113 family. Besides that, mannan side chain hydrolysing enzymes alpha-galactosidase (gla1; MZ702739) and beta-glucosidase (glu1; MZ702738) were also predicted.

Genome recoding strategies to improve cellular properties: mechanisms and advances.

The genetic code, once believed to be universal and immutable, is now known to contain many variations and is not quite universal. The basis for genome recoding strategy is genetic code variation that can be harnessed to improve cellular properties. Thus, genome recoding is a promising strategy for the enhancement of genome flexibility, allowing for novel functions that are not commonly documented in the organism in its natural environment. Here, the basic concept of genetic code and associated mechanisms for the generation of genetic codon variants, including biased codon usage, codon reassignment, and ambiguous decoding, are extensively discussed. Knowledge of the concept of natural genetic code expansion is also detailed. The generation of recoded organisms and associated mechanisms with basic targeting components, including aminoacyl-tRNA synthetase-tRNA pairs, elongation factor EF-Tu and ribosomes, are highlighted for a comprehensive understanding of this concept. The research associated with the generation of diverse recoded organisms is also discussed. The success of genome recoding in diverse multicellular organisms offers a platform for expanding protein chemistry at the biochemical level with non-canonical amino acids, genetically isolating the synthetic organisms from the natural ones, and fighting viruses, including SARS-CoV2, through the creation of attenuated viruses. In conclusion, genome recoding can offer diverse applications for improving cellular properties in the genome-recoded organisms.

Novel catalytic potential of a hyperthermostable mono­copper oxidase (LPMO-AOAA17) for the oxidation of lignin monomers and depolymerisation of lignin dimer in aqueous media.

Lytic polysaccharide monooxygenase (LPMO) are mono­copper enzymes known for the oxidative cleavage of recalcitrant polysaccharides with their intriguing and unique catalytic chemistry. Such impeccable oxidation potential has made them highly valuable in the enzymatic consortia for the degradation of ligno-cellulosic biomass. Bioinformatic analysis has revealed an unannotated LPMO gene in the genome of A. oryzae. Multiple sequence alignment showed the presence of conserved "histidine brace" of LPMO in the amino acid sequence of the enzyme. The enzyme, named as LPMO-AOAA17 was recombinantly expressed in E. coli BL21 and characterised for its substrate specificity. Recombinant enzyme did not show any characteristic cleavage of polysaccharides. However, it was found to be oxidising broad range of phenolic and non-phenolic monomers of lignin. Biochemical study revealed the optimum activity of LPMO-AOAA17 at pH 7 and was highly stable and active at 100 °C. The enzyme LPMO-AOAA17 was also observed to be stable after autoclaving at 121 °C and 15 psi. Thermal stability of the LPMO-AOAA17 was further confirmed through differential scanning calorimetry. GC-MS analysis has confirmed the catalysis of LPMO-AOAA17 for the depolymerisation of lignin dimer, guaicyl glycerol ß-guaicyl ether into guaiacol. This study has first time documented the identification of a hyperthermostable LPMO for oxidative cleavage of ß-O-4 linkage of lignin compounds to form aromatic products in aqueous media.

Chimeric bi-functional enzyme possessing xylanase and deacetylase activity for hydrolysis of agro-biomass rich in acetylated xylan.

Here, a chimeric bifunctional enzyme was developed for two activities xylanase and deacetylase. Chimeric enzyme was designed by combining the relevant amino acid stretches from two different parent sequences, such as polysaccharide/xylan deacetylase (ref id: MT682066) and xylanase (ref id WP_110897546.1). Five different hypothetical chimeras were developed and one of the best predicted chimeric protein GA_2(syn_SKYAP01) was synthesized. The GA_2(syn_SKYAP01) possessed the specific activity of 14.905 ±â€¯0.8 U/mg for deacetylase and 100.87 ±â€¯14.2 U/mg for xylanase. Optimum level of both the activities together was achieved at pH 5 and 60 °C. The chimeric protein was also found to be stable at higher temperature of 71°C. Functionality of the developed chimeric protein for both the activities was confirmed by the hydrolysis of commercial xylan into xylooligosaccharides and the release of acetic acid from glucose pentacetate and 7-amino cephalosporin. The designed bifunctional enzyme was found to be highly efficient.

Process scale-up of an efficient acid-catalyzed steam pretreatment of rice straw for xylitol production by C. Tropicalis MTCC 6192.

The present study focuses on operational parameters for the efficient acid catalyzed rice straw pretreatment process for xylitol production. 75.77 % xylose yield was attained when the 24 h presoaked rice straw (≤10 mm or ≤ 15 mm) in 1.5 % (v/v) H2SO4 was pretreated in the same reactor at 121 °C for 30 min. Neutralization with barium hydroxide produced insoluble salt and noticeably reduced HMF and furfurals. Xylitol yield of 0.6 g/g of xylose, was achieved by fermenting rice straw hydrolysate medium with C. tropicalis MTCC 6192. This two-step process of production of xylitol from xylose rich hydrolysate is much simpler and produced minimal inhibitors including organic acids such as acetic acid. This process is modified for upscaling at optimized parameters and will simultaneously minimize the pollution problem caused by rice straw and is also promising for commercial scale.

Recovery of nanosized silica and lignin from sugarcane bagasse waste and their engineering in fabrication of composite membrane for water purification.

Environmental benign catalytic process was developed for the valorisation of sugarcane bagasse into functional nanomaterials. Bagasse saccharification was carried out with an acid catalyst (H2SO4 0.5%, wt/wt) to separate sugars after pre-treatment of biomass with ethanol. Subsequently, a combination of peroxide and base (0.5% H2O2, wt/wt and 1% NaOH, wt/wt) was stacked to concurrently synthesise SiO2 (35 nm with 5.65% yield) and lignin (20 nm with 10.15% yield) from bagasse slurry. In the final step, precipitation using catalyst was completed to separate highly pure functional materials in powdered form. Zeta potential (ζ) of the synthesised materials was found to be - 35.6 mV for SiO2 and - 13.1 mV for lignin. Obtained silica and lignin nanomaterials were used in the fabrication of strong as well as flexible functional membrane for purification of solute particles and gases. The adsorption/desorption curve of the developed functional membrane showed type II isotherm with a H3 hysteresis loop. The observed Brunauer-Emmett-Teller surface area of the membrane was 400.3 m2/g. The pore size and pore volume as recorded by Barrett-Joyner-Halenda method was 25.5 nm and 0.624 cm3/g, respectively. Hence, the developed simple and sustainable process could be highly suitable for filtration of contaminated water and air purification.

Dual-Enzyme Metal Hybrid Crystal for Direct Transformation of Whey Lactose into a High-Value Rare Sugar D-Tagatose: Synthesis, Characterization, and a Sustainable Process.

A dual-enzyme metal-organic hybrid crystal was constructed through self-assembling of manganese phosphate embedded with ß-galactosidase and L-arabinose isomerase for facile synthesis of rare sugar D-tagatose. The synthesized crystal-like hierarchical system (MnHC@ß-Gal+L-AI) was extensively characterized for structural features and catalytic reactions. The results indicated that upon immobilization onto the hybrid crystal, the activity of ß-galactosidase and L-arabinose iomerase was enhanced by a factor of 1.6- and 1.5-fold, respectively. The developed MnHC@ß-Gal+L-AI exhibited excellent efficiency with a net equilibrium level conversion of low-cost substrate whey lactose (100%) into D-glucose (∼50%), D-galactose (∼25%), and D-tagatose (∼25%). In addition, the fabricated hybrid crystals displayed cofactor regeneration ability. Therefore, the developed hybrid system was observed to be efficiently reused more than 5 times in a batch level conversion. Hence, the developed dual-enzyme-based hybrid crystal provides a platform for direct transformation of whey lactose into rare sugar D-tagatose.

Characterization of a thermotolerant and acidophilic mannanase producing Microbacterium sp. CIAB417 for mannooligosachharide production from agro-residues and dye decolorization.

Mannanases are ubiquitous enzymes and are being explored for diverse industrial applications. In this study, a novel bacterial strain Microbacterium sp. CIAB417 was identified and characterized for extracellular production of mannanase. Microbacterium sp. CIAB417 was found to produce maximum mannanase after 36 h of incubation at 37 °C. Mannanase produced by the isolate was observed for maximum activity at optimum pH of 6 and optimum temperature of 50 °C. Crude mannanase was found to be capable of producing mannooligosachharides (MOS) by hydrolyzing hemicellulose from locust bean gum and Aloe vera. The produced MOS was characterized and found to be mixture of mannobiose to mannohexose units. Mannanase was also explored for decolorization of dyes. Bromophenol blue and coomassie blue R-250 were observed to be decolorized to the extent of 45.40 and 42.75%, respectively. Hence, the identified bacterial strain producing mannanase could be of great significance for applications in food and textile industry.

PkGPPS.SSU interacts with two PkGGPPS to form heteromeric GPPS in Picrorhiza kurrooa: Molecular insights into the picroside biosynthetic pathway.

Geranyl geranyl pyrophosphate synthase (GGPPS) is known to form an integral subunit of the heteromeric GPPS (geranyl pyrophosphate synthase) complex and catalyzes the biosynthesis of monoterpene in plants. Picrorhiza kurrooa Royle ex Benth., a medicinally important high altitude plant is known for picroside biomolecules, the monoterpenoids. However, the significance of heteromeric GPPS in P. kurrooa still remains obscure. Here, transient silencing of PkGGPPS was observed to reduce picroside-I (P-I) content by more than 60% as well as picroside-II (P-II) by more than 75%. Thus, PkGGPPS was found to be involved in the biosynthesis of P-I and P-II besides other terpenoids. To unravel the mechanism, small subunit of GPPS (PkGPPS.SSU) was identified from P. kurrooa. Protein-protein interaction studies in yeast as well as bimolecular fluorescence complementation (BiFC) in planta have indicated that large subunit of GPPS PkGPPS.LSUs (PkGGPPS1 and PkGGPPS2) and PkGPPS.SSU form a heteromeric GPPS. Presence of similar conserved domains such as light responsive motifs, low temperature responsive elements (LTRE), dehydration responsive elements (DREs), W Box and MeJA responsive elements in the promoters of PkGPPS.LSU and PkGPPS.SSU documented their involvement in picroside biosynthesis. Further, the tissue specific transcript expression analysis vis-à-vis epigenetic regulation (DNA methylation) of promoters as well as coding regions of PkGPPS.LSU and PkGPPS.SSU has strongly suggested their role in picroside biosynthesis. Taken together, the newly identified PkGPPS.SSU formed the heteromeric GPPS by interacting with PkGPPS.LSUs to synthesize P-I and P-II in P. kurrooa.

Genomic characterization provides genetic evidence for bacterial cellulose synthesis by Acetobacter pasteurianus RSV-4 strain.

There is ongoing quest to look for alternate sustainable and renewable biopolymers which can address the existing environmental issues. Bacterial cellulose could be one such option. Several organisms have been reported to produce bacterial cellulose. Among this, acetic acid bacteria (AAB) are reported to be one of the major producers of bacterial cellulose. Recently, we have identified an Acetobacter pasteurianus RSV-4 and reported to produce high tensile strength bacterial cellulose. In order to globally understand its genetic structure, a draft genome sequence of Acetobacter pasteurianus RSV-4 was performed in the present study. The assembled genome had 101 contigs contributing to a total length of 3.8 Mbp. Predicted coding DNA sequences were 3311, of which approximately 70% were assigned the functions. Genome level phylogenetic analysis revealed that RSV-4 belongs to A. pasteurianus. Glycolysis was found to be incomplete in the genome analysis of RSV-4, while the genes/enzymes involved in pentose-phosphate pathway were present. The final draft genome sequence lacked bacterial cellulose synthase (bcs) operon. However, the presence of operon was evident in raw genomic sequences by Sanger sequencing. Therefore, presence of bcs operon in Acetobacter pasteurianus RSV-4 has documented its potential for bacterial cellulose production.