Biodegradation and Micro- Scale Treatability Pattern of Loblolly Pine Heartwood Bioincised by Bacillus Subtilis and Physisporinus Vitreus

One strategy for improving the treatability of refractory wood species is biological incising, and its efficiency depends on how the microorganisms modify the porous structure of the wood. Evaluation of the bioincised wood treatability on a micro-scale can thus help to better understand the treatability enhancing mechanisms. In the present study, the biodegradation pattern and micro-scale treatability of Loblolly pine (Pinus taeda L.) heartwood were determined after bioincising with the white-rot fungus Physisporinus vitreus (Pers.: Fr.) P. Karsten isolate 136 and bacterium Bacillus subtilis UTB22. Oven-dried specimens with dimensions of 50 mm × 25 mm × 15 mm (L × T × R) were incubated with the microorganisms at (23±2) °C and (65±5) % relative humidity for six weeks. The control and exposed wood blocks were then pressure treated by 1 % fluorescent dye (fluorescein)-containing water to study the treatability pattern under a fluorescence microscope. The longitudinal and tangential air permeability and compression strength parallel to the grain of the specimens were also determined at the end of the incubation period. Scanning electron microscopic (SEM) studies showed that degradation by B. subtilis UTB22 was limited to the pit membranes, but the cell walls were also degraded to some extent by P. vitreus. The fungus caused a higher mass loss compared to the bacterium, whereas the permeability enhancing ability of the bacterium was more pronounced. The fluorescent dye tracer also showed that higher treatability with more uniformity was obtained by B. subtilis UTB22. The improvement in treatability by both microorganisms was mainly due to the degradation of the earlywood tracheids.

pLS20 is the archetype of a new family of conjugative plasmids harboured by Bacillus species

Conjugation plays important roles in genome plasticity, adaptation and evolution but is also the major horizontal gene-transfer route responsible for spreading toxin, virulence and antibiotic resistance genes. A better understanding of the conjugation process is required for developing drugs and strategies to impede the conjugation-mediated spread of these genes. So far, only a limited number of conjugative elements have been studied. For most of them, it is not known whether they represent a group of conjugative elements, nor about their distribution patterns. Here we show that pLS20 from the Gram-positive bacterium Bacillus subtilis is the prototype conjugative plasmid of a family of at least 35 members that can be divided into four clades, and which are harboured by different Bacillus species found in different global locations and environmental niches. Analyses of their phylogenetic relationship and their conjugation operons have expanded our understanding of a family of conjugative plasmids of Gram-positive origin.

Kin discrimination modifies fitness, spatial segregation and matrix sharing between strains with low relatedness in Bacillus subtilis biofilms

Microorganisms in nature form multicellular groups called biofilms. In biofilms bacteria embedded in a matrix of extracellular polymeric substances (EPS) interact intensely, due to their proximity to each other. Most studies have investigated genetically homogeneous biofilms, leaving a gap in knowledge on genetically heterogeneous biofilms. Recent insights show that a Gram-positive model bacterium, Bacillus subtilis, discriminates between strains of high (kin) and low (non-kin) phylogenetic relatedness, reflected in merging (kin) and boundaries (non-kin) between swarms. However, it is not clear how kinship between interacting strains affects their fitness, the genotype distribution, and the EPS sharing in floating biofilms (pellicles). To address this gap in knowledge we cultivate B. subtilis strains as mixtures of kin and non-kin strains in static cultures, allowing them to form pellicles. We show here that in non-kin pellicles only one strain’s fitness was reduced; at the same time, strains segregated into larger patches and exhibited decreased matrix sharing, as compared to kin and isogenic pellicles, in which both strains had comparable colony forming units (CFU) counts and more homogenous cell mixing. Overall, our results emphasize kin discrimination (KD) as a social behavior that shapes fitness, spatial segregation and sharing of the extracellular matrix in genetically heterogenous biofilms of B. subtilis.

Computational and synthetic biology approaches for the biosynthesis of antiviral and anticancer terpenoids from Bacillus subtilis.

: Recent advancements in medicinal research have identified several antiviral and anticancer terpenoids that are usually deployed as a source of flavor, fragrances and pharmaceuticals. Under the current COVID-19 pandemic conditions, natural therapeutics with least side effects are the need of the hour to save the patients, especially, which are pre-affected with other medical complications. Although, plants are the major sources of terpenoids; however, for the environmental concerns, the global interest has shifted to the biocatalytic production of molecules from microbial sources. The gram-positive bacterium Bacillus subtilis is a suitable host in this regard due to its GRAS (generally regarded as safe) status, ease in genetic manipulations and wide industrial acceptability. The B. subtilis synthesizes its terpenoid molecules from 1-deoxy-d-xylulose-5-phosphate (DXP) pathway, a common route in almost all microbial strains. Here, we summarize the computational and synthetic biology approaches to improve the production of terpenoid-based therapeutics from B. subtilis by utilizing DXP pathway. We focus on the in-silico approaches for screening the functionally improved enzyme-variants of the two crucial enzymes namely, the DXP synthase (DXS) and farnesyl pyrophosphate synthase (FPPS). The approaches for engineering the active sites are subsequently explained. It will be helpful to construct the functionally improved enzymes for the high-yield production of terpenoid-based anticancer and antiviral metabolites, which would help to reduce the cost and improve the availability of such therapeutics for the humankind.

Arganoleptic and proximate analysis of natto (yellow soy fermented food by the bacterium Bacillus Subtilis Natto)

This research aims to conduct organoleptic and proximate analysis of yellow soybean natto which is a food fermented from soybeans by Basillus subtillus natto. Natto is a traditional food originating from Japan that is classified as a probiotic food because it is consumed in fresh condition with the bacteria Basillus subtillus natto in it. Organoleptic analysis of natto in this study consisted of tests of texture, taste, color and aroma, while proximate analysis consisted of analysis of water content, protein content, fat content, carbohydrate content, and ash content. The results of the yellow soybean natto analysis show that the natto originating from Vedca Cianjur has a slimy sticky texture, brown color, a slightly sour and musty aroma like semangit tempeh and the savory taste of soybeans which is the distinctive aroma of natto. Proximate analysis shows that natto contains an average water level of 58.4± 0.50 %wb, average protein content of 20,1 ± 0.65 %wb, average fat content of 9.4 ± 0.42% wb, average carbohydrate content of 7.6 ± 0.47% wb, and the average ash content of 2.3 ± 0.19% wb. Keywords: physical, proximate, natto, Basillus subtillus natto

Rap-Phr systems in B. subtilis 3610 affect matrix gene expression and play a role in biofilm formation in vitro and on the plant root

Natural isolates of the soil-dwelling bacterium Bacillus subtilis form robust biofilms under laboratory conditions and colonize plant roots. B. subtilis biofilm gene expression displays phenotypic heterogeneity that is influenced by a family of Rap-Phr regulatory systems. Most Rap-Phr systems have been studied independently, in different genetic backgrounds and under distinct conditions, hampering true comparison of the Rap-Phr systems impact on bacterial differentiation. Here, we investigated each of the 12 Rap-Phr systems of B. subtilis NCIB 3610 for their role in biofilm formation. While Δ11 rap-phr mutants displayed increased matrix gene expression under biofilm inducing conditions, only some of the mutants demonstrated altered biofilm formation and colonization of Arabidopsis thaliana roots. Therefore, matrix gene expression does not directly correlate with biofilm formation in vitro and on the root. Our results suggest that each of the 12 Rap-Phr systems influences matrix gene expression, thereby allowing fine-tuning of the timing and level of matrix production in response to specific conditions, but additional factors also contribute to biofilm architecture and root colonization.

UJI AKTIVITAS ANTIBAKTERI SPRAY BAU KAKI EKSTRAK KULIT JERUK NIPIS (Citrus aurantifolia) DENGAN VARIASI Gelling agent TERHADAP BAKTERI Bacillus subtilis

ABSTRACT Sweat is produced by the apocrine glands, if infected by bacteria that play a role in the decay process will certainly produce foot odor. Some of the bacteria that cause, including Staphylococcus epidermis, Corynebacterium acne and there is one bacterium that causes pungent foot odor that is Bacillus subtilis. Bacillus subtilis enzyme leucine dehydrogenase produced the highest, resulting in isovaleric acid foot odor. Lime peel (Citrus aurantifolia) has the potential to be developed for the antibacterial active ingredient of foot odor contained in tannins, alkaloids and flavonoids. Spray can be effective for inhibition of feet due to water fleas or bacterial infections. The purpose of this research is to test the inhibitory zone of the preparation of foot odor spray ethanol extract of lime peel (Citrus aurantifolia) with variations of gelling agent. Bacterial inhibition zone testing on extracts of lime peel spray preparations using the disc method. This test was carried out on spray with extract concentration of 0% extract base carbopol, 0% extract base HPMC, 0.2% extract base carbopol, 0.2% extract base HPMC, 0.4% extract base carbopol, 0.4% extract base HPMC and positive control with an average inhibition zone of 9,13 mm, 9,12 mm, 11,86 mm, 11,29 mm, 13,17 mm, 12,30 mm, 8,13 mm against the bacterium Bacillus subtilis. Antibacterial test results were analyzed using ONE WAY ANOVA, the results of statistical analysis on the preparation of lime peel extract showed a significant inhibition zone difference of 0.000 (P = <0.05) between all concentrations. Lime peel extract spray is effective in inhibiting the bacterium Bacillus subtilis. Key words: Sweat of foot odor, Lime skin (Citrus aurantifolia), Spray, bacteri Bacillus subtilis

Chemotaxis under flow disorder shapes microbial dispersion in porous media

&lt;div&gt; &lt;div&gt; &lt;div&gt; &lt;p&gt;Natural soils are host to a high density and diversity of microorganisms, and even deep-earth porous rocks provide a habitat for active microbial communities. In these environ- ments, microbial transport by disordered flows is relevant for a broad range of natural and engineered processes, from biochemical cycling to remineralization and bioremediation. Yet, how bacteria are transported and distributed in the sub- surface as a result of the disordered flow and the associ- ated chemical gradients characteristic of porous media has remained poorly understood, in part because studies have so far focused on steady, macroscale chemical gradients. Here, we use a microfluidic model system that captures flow disorder and chemical gradients at the pore scale to quantify the transport and dispersion of the soil-dwelling bacterium Bacillus subtilis in porous media. We observe that chemotaxis strongly modulates the persistence of bacteria in low-flow regions of the pore space, resulting in a 100% increase in their dispersion coefficient. This effect stems directly from the strong pore-scale gradients created by flow disorder and demonstrates that the microscale interplay between bacterial behaviour and pore-scale disorder can impact the macroscale dynamics of biota in the subsurface.&lt;/p&gt; &lt;/div&gt; &lt;/div&gt; &lt;/div&gt;