Pectinase Activity Research Articles

Influence of the Cellular Ultrastructure and Enzyme Activity of the Leaf Sheath on Spontaneous Defoliation in Sugarcane

Spontaneous defoliation improves the harvesting efficiency and yield of sugarcane. Here, we investigated the ultrastructural changes and pectinase and cellulase activity in the third, fifth, and seventh leaf sheaths in four sugarcane varieties with varying spontaneous defoliation performance during maturation. At the early and middle stages of spontaneous defoliation, the cells in the abscission zones of the third, fifth, and seventh leaf sheaths were degrading. At the late stage, no complete organelles and hollow or broken spots in the cell walls were observed in the abscission zone cells of defoliation-prone varieties, while complete organelles and intact cell walls were present in the abscission zone cells at the same leaf positions in defoliation-resistant varieties. From the early to late stages, defoliation-prone varieties had higher pectinase activity in the abscission zones of the fifth and seventh leaf sheaths. At the early stage of defoliation, defoliation-prone varieties had significantly higher cellulase activity in the abscission zones of the third, fifth, and seventh leaf sheaths. Correlation analysis showed that the spontaneous defoliation rate was significantly positively correlated with pectinase activity in the leaf sheaths. In conclusion, the spontaneous defoliation of sugarcane was closely related to changes in cell morphology and pectinase activites in leaf sheaths.

Enzymase Activity of Gut Microbes Isolated from the Rugose Spiraling Whitefly Aleurodicus rugioperculatus

This study investigated the enzymatic diversity among various bacterial isolates of Rugose Spiraling Whitefly (Aleurodicus rugioperculatus), shedding light on their potential industrial applications. Notably, Bacillus cereus (MRSW01) exhibited remarkable amylase and lipase activities, aligning with its reputation as a prominent amylase producer. These enzymes are crucial in the food industry, particularly in starch and lipid degradation processes. Pseudomonas helleri (CHRSW028) demonstrated substantial cellulase activity, essential for breaking down cellulose in plant materials, suggesting its relevance in biofuel production and waste management. Pseudomonas psychrophila (CRSW024) stood out with the highest pectinase and significant lipase activities, both of which find applications in the food and textile industries and the hydrolysis of fats and oils, respectively. Proteus vulgaris strains MRSW05 and CHRSW02 displayed significant amylase, cellulase, and protease activities, making them versatile candidates for various industrial applications, including detergent formulations and bioremediation processes. Conversely, Hafnia paralvei exhibited comparatively lower enzymatic activities, indicating limited industrial potential. The rich enzymatic diversity within these bacterial isolates and highlight their potential contributions to various industrial sectors, ranging from food and textiles to biofuel production and waste management. Such insights can inform the development of biotechnological applications and processes, ultimately benefitting both industrial and environmental domains.

Trichoderma-derived emodin competes with ExpR and ExpI of Pectobacterium carotovorum subsp. carotovorum to biocontrol bacterial soft rot.

Quorum sensing inhibitors (QSIs) are an emerging control tool that inhibits the quorum sensing (QS) system of pathogenic bacteria. We aimed to screen for potential QSIs in the metabolites of Trichoderma and to explore their inhibitory mechanisms. We screened a strain of Trichoderma asperellum LN004, which demonstrated the ability to inhibit the color development of Chromobacterium subtsugae CV026, primarily attributed to the presence of emodin as its key QSI component. The quantitative polymerase chain reaction with reverse transcription results showed that after emodin treatment of Pectobacterium carotovorum subsp. carotovorum (Pcc), plant cell wall degrading enzyme-related synthetic genes were significantly downregulated, and the exogenous enzyme synthesis gene negative regulator (rsmA) was upregulated 3.5-fold. Docking simulations indicated that emodin could be a potential ligand for ExpI and ExpR proteins because it exhibited stronger competition than the natural ligands in Pcc. In addition, western blotting showed that emodin attenuated the degradation of n-acylhomoserine lactone on the ExpR protein and protected it. Different concentrations of emodin reduced the activity of pectinase, cellulase, and protease in Pcc by 20.81%-72.21%, 8.38%-52.73%, and 3.57%-47.50%. Lesion size in Chinese cabbages, carrots and cherry tomatoes following Pcc infestation was reduced by 10.02%-68.57%, 40.17%-88.56% and 11.36%-86.17%. Emodin from T. asperellum LN004 as a QSI can compete to bind both ExpI and ExpR proteins, interfering with the QS of Pcc and reducing the production of virulence factors. The first molecular mechanism reveals the ability of emodin as a QSI to competitively inhibit two QS proteins simultaneously. © 2023 Society of Chemical Industry.

Screening and Production of Industrially Relevant Enzymes by Bacillus paranthracis Strain MHDS3, a Potential Probiotic

The digestive process and intestinal protein absorption are influenced by a variety of factors. Due to their numerous health advantages, including potential favorable effects on protein digestion and absorption, probiotics have gained increased attention in recent years. Probiotics can control the intestinal microflora, which in turn affects the intestinal bacteria responsible for proteolysis. Additionally, certain probiotics can release exoenzymes that aid in the digestion of proteins and others can stimulate the host’s digestive protease and peptidase activity. By boosting transport and enhancing the epithelium’s capacity for absorption, probiotics can also improve the absorption of tiny peptides and amino acids as well as lessen detrimental protein fermentation, which lowers the toxicity of metabolites. The present study explored the production of enzymes by Bacillus paranthracis strain MHDS3, a probiotic candidate isolated from Pellaea calomelanos. Bacillus paranthracis displayed enzyme activities of amylase (31,788.59 IU), cellulase (4487.486 IU), and pectinase (13.98986 IU) through submerged fermentation. The CAZyme analysis of B. paranthracis revealed 16 CAZyme gene clusters associated with cellulose, amylase, and pectinase activity. Thus, B. paranthracis is a promising probiotic strain that can produce enzymes with biotechnological applications.

Saccharification of Agricultural Wastes and Clarification of Orange Juice by Penicillium rolfsii CCMB 714 Pectinase

Pectinases are enzymes used in several industrial processes. Seven agroindustrial wastes—jackfruit seed meal (Artocarpus heterophyllus), cocoa seed peel (Theobroma cacao), cocoa husks (Theobroma cacao), passion fruit husks (Passiflora edulis), mangosteen husks (Garcinia mangostana), malt residue (Hordeum vulgare) and the peach palm waste (Bactris gasipaes Kunth.)—were evaluated to produce a crude extract containing pectinase activity by Penicillium rolfsii CCMB 714. The jackfruit seed meal was chosen as the best substrate for solid-state fermentation, which was optimized with 4 mL of water as a wetting agent for 2 days at 35 °C and with a 0.5% nitrogen source, whereby the pectinase production increased by 44% (362.09 U/g). The obtained crude extract was characterized and applied to wastes saccharification and orange juice clarification. The pectinase showed better activity at a pH of 3.0 to 5.0 and 55 °C, it stably maintained over 80% of activity at 30–50 °C for up to 60 min and 1 mM CuSO4 increased the pectinase activity by 17%. The saccharification of agroindustrial wastes (cocoa husks, mangosteen husks and passion fruit husks) resulted in 126.55 µmol/mL of reducing sugars from passion fruit husks, which represents an increase of 126% after optimization (45 °C for 22 h). For the clarification of orange juice, it was possible to reduce the absorbance of the juice by 55%. These results elucidate the potential of the low-cost pectinase solution from P. rolfsii CCMB 714 cultivated in jackfruit seed meal for both the enzymatic pretreatment of plant biomass and the application in beverage industries.

Effects of Biodegradable Liquid Film (BLF) on Cold Resistance in Grapevine Revealed by Metabolomic Analysis

Low temperatures are among the most important abiotic stresses, severely affecting vine growth and development. In order to overwinter safely, grape growers pay high labor costs, which are unsustainable in modern agriculture. Biodegradable liquid film (BLF) is an environmentally friendly material that assists grapevines to withstand the cold. In this experiment, Cabernet Sauvignon from Junding Winery was used as material for field trials. The regulatory effect of BLF on the cold resistance of grapevines was analyzed, and its mechanism of action was explored using metabolomics. The results showed that BLF significantly increased the activity of superoxide dismutase, the content of proline and ascorbic acid, reducing sugar, sucrose, and soluble sugar, and also decreased the content of malondialdehyde. In addition, BLF significantly increased the activity of invertase and decreased the activity of pectinase and phosphofructokinase. Metabolomics data showed that BLF improved cold resistance in grapevines by affecting lipids, flavonoids, amino acids, and nucleotide metabolic pathways.

Space exposure enhanced pectin-degrading enzymes expression and activity in Aspergillus costaricaensis.

Aspergillus is a well-studied fungal genus that is widely used in the processing of plant biomass in industries. This study investigated the effects of space exposure on the ability of Aspergillus costaricaensis, a filamentous fungus isolated from rotten orange peel, to degrade pectin. These fungal spores were carried into space by the Long March 5B carrier rocket and exposed to cosmic radiation for 79h. After the flight, these spores were resuscitated, and then the growing strains were screened with pectin as the sole carbon source, and the pectinase activity was evaluated. A mutant with increased biomass accumulation ability and pectin-degrading activity compared to the ground control strain was obtained. Comparative transcriptome analysis revealed that several CAZymes genes were significantly upregulated in the mutant, especially those related to pectin degradation. Among the 44 pectinases identified from the annotated genome, 42 were up-regulated. The activities of these pectinases are able to synergistically break down the structure of pectin. In addition, the expression of some genes involved in metabolism, sugar transport, and stress response was altered. These results imply that space exposure might serve as a potential mutagenesis breeding technique, offering the opportunity to acquire biomass-degrading microbial strains with potential for industrial application.

Effect of calcium spray at flowering combined with post-harvest 1-MCP treatment on the preservation of grapes

These tests were carried out to find out how calcium and 1-MCP treatment affected the preservation of grapes, as grapes are highly susceptible to decay during post-harvest storage. The grapes were treated with 5 g/L calcium at the flowering stage, followed by 1 μL/L 1-MCP treatment after harvesting.When grapevines were treated with a combination of calcium and 1-MCP, the marketable fruit rate (At day 56 of storage, the 1-MCP + Ca2+ treatment group was still 93%, an increase of 29.03% compared to the control group.) and quality improved (At day 28 of storage, the VC content of the 1-MCP + Ca2+ treated group was 4.35 mg/100g, an increase of 25.01% compared to the control group.), while the fruit weight loss rate decreased (At day 56 of storage, the weight loss of the control group was 6.97%, an increase of 39.43% compared to the 1-MCP + Ca2+ treated group.).According to the experimental results, there are several reasons for this. First, in the early stages of fruit storage, the concentration of soluble pectin and soluble fiber, as well as the activities of pectinase and cellulase (related gene levels) were decreased. Secondly, the activity of antioxidant enzymes was increased, while MDA content was decreased. Third, during fruit storage, the respiratory intensity and ethylene release rate were reduced, as was the activity of energy metabolism enzymes. As a result, the aging and deterioration of the fruit during storage were delayed. Principal component analysis revealed that the calcium and 1-MCP combination therapy slowed the decline in grape berry quality, followed by the calcium-treated and 1-MCP-treated fruits. In contrast, grape berry quality declined the most rapidly in the control group.

Effect of spirulina fortification on the digestive protease, carbohydrases and cocoons economic traits of mulberry silkworm Bombyx mori

Bombyx mori, the silkworm, is a voracious feeder that relies on digestive enzymes for mulberry digestion and its conversion in to silk. In the current study, fifth-instar larvae were given 2% spirulina supplementation with commercially graded spirulina samples, and a few digestive enzymes and cocoon traits were examined. The treatment groups of silkworms T1-control, T2-supplemented with spirulina powder graded for animal dietary consumption, T3- graded for human dietary consumption and T4-spirulina graded for medicinal applications. Spirulina supplementation was tested in silkworms for digestive protease, carbohydrases and cocoon traits. The results shows that the total protein content percentage difference (PD) in the gut wall was increased by 2.79% in T3, 1.96% in T4, and 0.78% in T2 compared to T1 (control). A similar trend was noticed in the gut content, with the PD of 15.81% in T3, 7.51% in T4, and 3.95% in T2. In total carbohydrate content, observed PD of 16.35% in T2, 11.27% in T3, and 9.38% in T4, while the gut content was 13% both in T2 and T3, and 1.22% in T4. The protease activity PD of gut wall tissue has 21.99% in T3, 5.13% in T2, and 4.30% in T4; similarly, the gut content has a PD of 112.38% in T3, 106.12% in T4, and 86.41% in T2. The amylase activity have shown highest PD in T4 (33.43%), T3 (23.37%), and moderate in T2 (19.23%) in the gut wall, and 93.10% in T3, 66.44% in T2, and 14.92% in T4 of gut content. Enzymes such as sucrase, cellulase, and pectinase have also improved with spirulina fortification. The sucrase activity in the gut wall and gut content were, respectively, 7.99% and 80.73% in T3 treatment. Noteworthy, the T2 showed 37.69% in the gut wall and 24.54% in the gut content for the cellulase activity. Unlike cellulase, pectinase activity has been observed with a PD of 93.15% in the gut wall and 64.63% in gut content. The study further confirms that the additional fortification of spirulina will have a beneficial effect on the digestive cells of the silkworm, Bombyx mori, resulting in the highest rate of enzyme activity and in turn, increasing survivability.

Screening and Analysis of Antifungal Strains Bacillus subtilis JF-4 and B. amylum JF-5 for the Biological Control of Fusarium Wilt of Banana.

This study aimed to identify the antagonistic bacteria from the rhizosphere of healthy bananas that can effectively suppress the Fusarium wilt of banana, and to further investigate the inhibitory mechanism. The primary and secondary screening techniques were implemented using the double-plate and fermentation antagonism methods. The strain was identified based on physiological and biochemical tests, 16S rRNA gene sequencing, and specific gene amplification. The effects of crude extract on the protein content, lipid peroxidation, and pectinase activity of mycelia were determined from the identified isolates. Two antagonistic bacteria, JF-4 and JF-5, were screened and initially identified as Bacillus subtilis (GenBank: OR125631) and B. amylum (GenBank: OR125632). The greenhouse experiment showed that the biological control efficiency of the two antagonists against the Fusarium wilt of banana was 48.3% and 40.3%, respectively. The catalase content produced by lipid peroxidation increased significantly after treatment with the crude extracts of JF-4 and JF-5 at concentrations of 0.69 μmol/L and 0.59 μmol/L, respectively. The protein and ergosterol content and pectinase activity decreased significantly. The two antagonistic bacteria might inhibit the growth of pathogens by enhancing lipid peroxidation and decreasing the synthesis of cell metabolites. Twenty compounds were identified by gas chromatography-mass spectrometry (GC-MS). B. subtilis JF-4 was further sequenced and assembled to obtain a complete circular chromosome genome of 681,804,824 bp. The genome consisted of a 4,310,825-bp-long scaffold. The findings of this study may help elucidate the mechanism behind this biocontrol isolate.

Impact of dormancy periods on some physiological and biochemical indices of potato tubers.

Storage of potato tubers is an essential stage of the supply chain, from farm to consumer, to efficiently match supply and demand. However, the quality and yield of potatoes are influenced by physiological changes during storage. This study tested the physiological and biochemical indices in three potato varieties (YunSu 108, YunSu 304 and YunSu 306) during their dormancy periods. Three potato varieties with different dormancy periods were used to follow changes in starch, protein and several enzymes during storage. The starch and sugar content of the long-dormant variety (YunSu 108, LDV) were stable, whereas those of the short-dormant variety (YunSu 306, SDV) were variable. Starch synthase activity in the three varieties was initially high, then decreased; the starch content of LDV was relatively stable, that of the medium-dormant variety (YunSu 304, MDV) increased with storage time and peaked at sprouting, and that of SDV was low but variable. The sucrose synthase activity of LDV was significantly higher (p<0.05) than MDV and SDV in the middle storage period. Two spikes were observed in the invertase activity of SDV, whereas those of MDV and LDV were stable. The reducing sugar content of LDV increased significantly before sprouting, that of MDV slowly decreased and that of SDV dropped sharply. During the whole storage period, pectinase activity in LDV did not change significantly, whereas pectinase in MDV and SDV decreased. The cellulase and protein contents initially increased and then decreased in LDV, and steadily decreased in MDV and SDV. The metabolic indices related to starch and sugar in the LDV were relatively stable during storage, whereas those of the SDV varied greatly. SDV showed increased sucrose, reducing sugars and cellulose; LDV PCA plots clustered in the positive quadrant of PC1 and the negative quadrant of PC2, with increased protein, sucrose synthase and starch; MDV had increased soluble starch synthase.

Promotive effect of phytosulfokine - peptide growth factor - on protoplast cultures development in Fagopyrum tataricum (L.) Gaertn

BackgroundFagopyrum tataricum (Tartary buckwheat) is a valuable crop of great nutritional importance due to its high level of bioactive compounds. Excellent opportunities to obtain plants with the high level or the desired profile of valuable metabolites may be provided by in vitro cultures. Among known in vitro techniques, protoplast technology is an exciting tool for genetic manipulation to improve crop traits. In that context, protoplast fusion may be applied to generate hybrid cells between different species of Fagopyrum. To apply protoplast cultures to the aforementioned approaches in this research, we established the protoplast-to-plant system in Tartary buckwheat.ResultsIn this work, cellulase and pectinase activity enabled protoplast isolation from non-morphogenic and morphogenic callus (MC), reaching, on average, 2.3 × 106 protoplasts per g of fresh weight. However, to release protoplasts from hypocotyls, the key step was the application of driselase in the enzyme mixture. We showed that colony formation could be induced after protoplast embedding in agarose compared to the alginate matrix. Protoplasts cultured in a medium based on Kao and Michayluk supplemented with phytosulfokine (PSK) rebuilt cell walls, underwent repeated mitotic division, formed aggregates, which consequently led to callus formation. Plating efficiency, expressing the number of cell aggregate formed, in 10-day-old protoplast cultures varied from 14% for morphogenic callus to 30% for hypocotyls used as a protoplast source. However plant regeneration via somatic embryogenesis and organogenesis occurred only during the cultivation of MC-derived protoplasts.ConclusionsThis study demonstrated that the applied protoplast isolation approach facilitated the recovery of viable protoplasts. Moreover, the embedding of protoplasts in an agarose matrix and supplementation of a culture medium with PSK effectively stimulated cell division and further development of Tartary buckwheat protoplast cultures along with the plant regeneration. Together, these results provide the first evidence of developing a protoplast-to-plant system from the MC of Fagopyrum tataricum used as source material. These findings suggest that Tartary buckwheat’s protoplast cultures have potential implications for the species’ somatic hybridization and genetic improvement.

Isolation, identification, and enzyme screening of fungi infested various vegetables in the local markets of Visakhapatnam, Andhra Pradesh

This study aimed to examine the fungi present in fruits and vegetables obtained from the local vegetable markets, Visakhapatnam and assess their enzymatic activity. seven fungal pathogens responsible for vegetable spoilage were isolated using sterilization and spread plate techniques on potato dextrose agar (PDA) medium. The isolated fungi were identified based on macroscopic and microscopic characteristics. The identified fungal strains included Aspergillus, Curvularia, Alternaria, Cladosporium, Fusarium, sclerotinia, Mucor, Penicillium, and Rhizopus. Only three selected strains were tested for extracellular amylase, pectinase and cellulase activity, which were showing 15mm,20mm,30mm clear zone capability. These findings provide essential information about the degradative properties of filamentous fungi and their secretion of extracellular enzymes. The study also highlights the presence of toxigenic fungi in local vegetables, emphasizing the importance of removing spoiled fruits to prevent the accumulation of toxins associated with fungal growth.

Efficiency of Lactiplantibacillus plantarum JT-PN39 and Paenibacillus motobuensis JT-A29 for Fermented Coffee Applications and Fermented Coffee Characteristics.

To develop a process for low-cost and ecologically friendly coffee fermentation, civet gut bacteria were isolated and screened to be used for fermentation. Among 223 isolates from civet feces, two bacteria exhibited strong protease, amylase, lipase, pectinase, and cellulase activities. By analyzing 16S rDNA phylogeny, those bacteria were identified to be Lactiplantibacillus plantarum JT-PN39 (LP) and Paenibacillus motobuensis JT-A29 (PM), where their potency (pure or mixed bacterial culture) for fermenting 5 L of arabica parchment coffee in 48-72 h was further determined. To characterize the role of bacteria in coffee fermentation, growth and pH were also determined. For mixed starter culture conditions, the growth of PM was not detected after 36 h of fermentation due to the low acid conditions generated by LP. Coffee quality was evaluated using a cupping test, and LP-fermented coffee expressed a higher cupping score, with a main fruity and sour flavor, and a dominant caramel-honey-like aroma. Antioxidant and anti-foodborne pathogenic bacteria activity, including total phenolic compounds of PM and LP fermented coffee extracts, was significantly higher than those of ordinary coffee. In addition, LP-fermented coffee expressed the highest antibacterial and antioxidant activities among the fermented coffee. The toxicity test was examined in the murine macrophage RAW 264.7 cell, and all fermented coffee revealed 80-90% cell variability, which means that the fermentation process does not generate any toxicity. In addition, qualifications of non-volatile and volatile compounds in fermented coffee were examined by LC-MS and GC-MS to discriminate the bacterial role during the process by PCA plot. The flavors of fermented coffee, including volatile and non-volatile compounds, were totally different between the non-fermented and fermented conditions. Moreover, the PCA plot showed slightly different flavors among fermentations with different starter cultures. For both the cupping test and biological activities, this study suggests that LP has potential for health benefits in coffee fermentation.

Precise utilization of fruit and vegetable waste as a substrate for the multienzyme production by Bacillus subtilis NG105 and Trichoderma asperelllum NG125

We earlier identified Bacillus subtilis NG105 and Trichoderma asperelllum NG125 isolated from fruit and vegetable wastes (FVWs) and established that multienzyme activity viz pectinase, cellulase and amylase (PC&A) activity was localized exclusively in cell exudates (CEs). In this study, we evaluated the best rotten or leftover FVWs of Bael, Guava, Mosambi, Beetroot, Banana, Aonla, Mango and Cabbage as potential substrates under solid-state fermentation (SSF) for isolated microbial strains to multi-enzyme production. The results showed that after SSF, the multienzyme activity of microbial CEs of both NG105 (394.6, 296.1, 341.4 μmol ml−1min−1 of PC&A respectively) and NG125 (420.5, 347.3, 330.7 μmol ml−1min−1 of PC&A respectively) extracted from mosambi peel performed best. The multienzyme present in CEs was further partially purified using five different chemical solvents; acetone, trichloroacetic acid, ammonium sulphate (70%), ethanol, and n-propanol. Results revealed that partially purified multienzyme (PPM) of both NG105 (415.2, 425.4, 414.3 μmol ml−1min−1 of PCA respectively) and NG125 strain (528.5, 509.2, 467.6 μmol ml−1min−1 of PC&A respectively) found to be highest in PPM extracted with acetone. The result indicates that mosambi peel may be used as the best FVWs as the substrate for our isolated strains for multienzyme production and the acetone purification method was well suited for the enhancement of the enzymatic activity. Moreover, the produced multienzyme (in CEs form) either in the system in which they are produced (eg. juice clarification) or extracted and partially purified form may be further utilized for other purposes (eg. food, animal feed, bio-fuel, detergent, industries etc).

Biosynthesis of titanium dioxide nanoparticles using probiotic bacterial strain, Lactobacillus rhamnosus, and evaluate of their biocompatibility and antifungal activity

The main goal of the current study is to biosynthesize titanium dioxide nanoparticles (TiO2-NPs) using green approach to biocontrol of different fungal strains isolated from historical Description of Egypt book. Nineteen fungal strains were isolated from deteriorated parts and identified by the traditional and molecular methods as Aspergillus flavus (8-isolates), Aspergillus versicolor (2-isolates), Aspergillus ustus (4-isolates), Aspergillus chinensis (2-isolates), Penicillium citrinum (2-isolates), and Penicillium chrysogenum (1-isolate). These fungal strains showed high cellulase, amylase, pectinase, and gelatinase activities which have a significant role in biodeterioration. The biomass filtrate of probiotic strain, Lactobacillus rhamnosus, was used to fabricate TiO2-NPs which characterized by UV-Vis, FT-IR, XRD, TEM, SEM, EDX, DLS, and zeta potential. The obtained data showed the successful formation of spherical and anatase phase NPs with sizes of 3–7 nm and zeta potential values of – 19.9 and – 36.8 mV. The main components of as-formed nanomaterial were Ti and O with weight percentages of 55.91 and 46.25, respectively. The biocompatibility of synthesized TiO2-NPs was investigated toward two normal cell lines, WI38 and HFB4, which reveal the low toxicity at high concentrations (IC50 > 300 μg mL–1). Therefore, concentrations ≤ 300 μg mL–1 were used to biocontrol of isolated fungi. Data showed the promising activity of various concentrations (300, 200, and 100 μg mL–1) of TiO2-NPs to inhibit the growth of fungal strains with varied inhibition zones and dose-dependent manner. This study exhibited the efficacy of probiotic bacterial strains in the synthesis of TiO2-NPs that can be used to preserve historical books from fungal deterioration.Graphical

Screening and optimization of extracellular pectinase produced by Bacillus thuringiensis SH7

Abstract The objective of the current research was to identify and evaluate the possibility of production of pectinase, also known as pectin degrading enzymes, from indigenous bacterial strains. Qualitative screening of isolated bacterial strains showed that among 29 bacterial strains, 5 have maximum enzymatic activity. The highest pectinase producing strains were quantitatively analyzed for enzyme production. SH7 strain was found as highest pectinase producer (0.77 IU/mL) that was further analyzed to molecular level by amplification of 16s rRNA. It was found 100% similar with other reported strains of Bacillus thuringiensis. Medium optimization was performed to optimize fermentation conditions for maximum enzyme yield. An experimental design containing 12 experimental runs was designed by Plackett–Burman design (PBD). Maximum pectinase activity was obtained at 45°C after 24 h when the growth medium was supplemented with 2.5% nitrogen, 5.0% substrate, MgSO4 as metal ion, 1% inoculum size, and pH was adjusted to 6. Factorial regression analysis of the PBD design was performed and the overall design was also found significant in terms of R square value. In PBD, the most significant factors for production were temperature, pH, metal ion concentration, and nitrogen source. Central composite design (CCD) design consisting of 26 experimental runs was employed to optimize these four significant factors. The overall model summary showed maximum pectinase activity (19.2 IU/mL) at 37°C temperature, 0.08 NaCl, 1.7% nitrogen source, and pH 8.4. In CCD, NaCl, nitrogen source, and pH were also reported as significant factors by the Pareto chart, probability plots, and 3D interactions.

Isolation and characterization of reductive acetogens from rumen fluid samples of Murrah buffaloes.

In the present study, attempts have been made to isolate reductive acetogens from the rumen fluid samples of Murrah buffaloes (Bubalus bubalis). Out of 32 rumen samples 51 isolates were isolated, and based on autotrophic growth for production of acetate and presence of formyltetrahydrofolate synthetase gene (FTHFS) 12 isolates were confirmed as reductive acetogens. Microscopic observations showed that ten isolates as Gram-positive rods (ACB28, ACB29, ACB66, ACB73, ACB81, ACB91, ACB133, ACB229, ACB52, ACB95) and two isolates as Gram-positive cocci (ACB19, ACB89). All isolates tested negative for catalase, oxidase, and gelatin liquefaction, whereas the production of H2S was detected for two (ACB52 and ACB95) of the above isolates. All these isolates showed autotrophic growth from H2 and CO2, and heterotrophic growth with different fermentable sugars, viz., d-glucose, D-fructose, and D-trehalose but failed to grow on salicin, raffinose, and l-rhamnose. Out of the isolates, two showed amylase activity (ACB28 and ACB95), five showed CMCase activity (ACB19, ACB28, ACB29, ACB73 and ACB91), three showed pectinase activity (ACB29, ACB52 and ACB89), whereas none of the isolates was found positive for avicellase and xylanase activity. Based on 16S rDNA gene sequence analysis, the isolates showed their phylogenetic relationship with maximum similarity up to 99% to different strains of earlier reported known acetogens of clostridia group including Clostridium sp. (6), Eubacterium limosum (1), Ruminococcus sp. (1) and Acetobacterium woodii (1) except one, i.e., Vagococcus fluvialis. The results indicate that reductive acetogens isolated from the rumen fluid samples of Murrah buffalos are both autotrophic and heterotrophic in nature and further investigations are required to exploit and explore their potential as an alternate hydrogen sink.

PdGpaA controls the growth and virulence of Penicillium digitatum by regulating cell wall reorganization, energy metabolism, and CDWEs production

Penicillium digitatum could infect citrus and cause devastating green mold disease. One of the essential parts of the G protein is the Gα subunit, which is essential to signal transduction in filamentous fungi but has not been reported in P. digitatum. In this study, PdGpaA was identified as a homolog of Gα in P. digitatum, and deletion of the PdGpaA gene significantly accelerated early-stage spore germination and inhibited late-stage hyphal growth and conidiophore formation. The ΔPdGpaA strain showed faster growth in sodium dodecyl sulfate (SDS) and calcofluor white (CFW) but more sensitivity to Congo red (CR). We predicted that cell wall integrity had been compromised due to cell wall rearrangement. Moreover, the increased quantity of septa and the reorganization of cell walls were confirmed by CFW staining and quantitative real-time PCR analysis. Deletion of the PdGpaA gene increased intracellular reactive oxygen species (ROS)and mitochondrial deterioration, which obstruct the TCA cycle and hinder energy metabolism. A pathogenicity test revealed that the lesion diameter was decreased by 90.62 % in the ΔPdGpaA strain, probably as the result of a decline in the activity of pectinase and cellulase. In addition, the ΔPdGpaA strain was more sensitive to prochloraz, KCl and H2O2. In conclusion, this study provides multiple functions for the PdGpaA gene, which might have broad application space and prospects in the control of citrus green mold.

Effect of Agar and Some Natural Oils Coating on Pectinase Activity, Antioxidant Content, Storability and Fruit Properties of Pomegranate Wonderful Cultivar

Effect of Agar and Some Natural Oils Coating on Pectinase Activity, Antioxidant Content, Storability and Fruit Properties of Pomegranate Wonderful Cultivar