Factors affecting the production and molecular weight of levan in enzymatic synthesis by recombinant <scp><i>Bacillus subtilis</i></scp> levansucrase <scp>SacB‐T305A</scp>

Hou, Yuanyuan; Huang, Fei; Huí, Yang; Cong, Hao; Zhang, Xi; Xie, Xiao; Yang, Haibo; Tong, Qiuping; Luo, Na; Zhu, Ping; Ju, Meng

doi:10.1002/pi.6112

Cited by 11 publications

(4 citation statements)

References 31 publications

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“…The numerical values of BL are summarized in Table 3, indicating that BL biosynthesized using S. salivarius K12 had an M w 500 times larger than BL obtained by L. mesenteroides DSM 20343, whose values corresponded to 15.435 × 10 4 and 26.6 kDa, respectively. The obtained data reveal that BL produced by L. mesenteroides DSM 20343 is classified as a low-molecular-weight polymer, according to Hou et al [69]. However, this is the first report demonstrating the ability of S. salivarius K12 to produce BL over 15 million Da under standardized processing and operational conditions.…”

Section: Characterization Of Bacterial Levan Biosynthesized By Strept...mentioning

confidence: 75%

Elaboration of Nanostructured Levan-Based Colloid System as a Biological Alternative with Antimicrobial Activity for Applications in the Management of Pathogenic Microorganisms

Radenkovs,

Valdovska,

Galina

et al. 2023

Nanomaterials

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Considering the documented health benefits of bacterial exopolysaccharides (EPSs), specifically of bacterial levan (BL), including its intrinsic antimicrobial activity against certain pathogenic species, the current study concentrated on the development of active pharmaceutical ingredients (APIs) in the form of colloid systems (CoSs) containing silver nanoparticles (AgNPs) employing in-house biosynthesized BL as a reducing and capping agent. The established protocol of fermentation conditions implicating two species of lactic acid bacteria (LAB), i.e., Streptococcus salivarius K12 and Leuconostoc mesenteroides DSM 20343, ensured a yield of up to 25.7 and 13.7 g L−1 of BL within 72 h, respectively. An analytical approach accomplished by Fourier-transform infrared (FT-IR) spectroscopy allowed for the verification of structural features attributed to biosynthesized BL. Furthermore, scanning electron microscopy (SEM) revealed the crystalline morphology of biosynthesized BL with a smooth and glossy surface and highly porous structure. Molecular weight (Mw) estimated by multi-detector size-exclusion chromatography (SEC) indicated that BL biosynthesized using S. salivarius K12 has an impressively high Mw, corresponding to 15.435 × 104 kilodaltons (kDa). In turn, BL isolated from L. mesenteroides DSM 20343 was found to have an Mw of only 26.6 kDa. Polydispersity index estimation (PD = Mw/Mn) of produced BL displayed a monodispersed molecule isolated from S. salivarius K12, corresponding to 1.08, while this was 2.17 for L. mesenteroides DSM 20343 isolate. The presence of fructose as the main backbone and, to a lesser extent, glucose and galactose as side chain molecules in EPS hydrolysates was supported by HPLC-RID detection. In producing CoS-BL@AgNPs within green biosynthesis, the presence of nanostructured objects with a size distribution from 12.67 ± 5.56 nm to 46.97 ± 20.23 was confirmed by SEM and energy-dispersive X-ray spectroscopy (EDX). The prominent inhibitory potency of elaborated CoS-BL@AgNPs against both reference test cultures, i.e., Pseudomonas aeruginosa, Escherichia coli, Enterobacter aerogenes, and Staphylococcus aureus and those of clinical origin with multi-drug resistance (MDR), was confirmed by disc and well diffusion tests and supported by the values of the minimum inhibitory and bactericidal concentrations. CoS-BL@AgNPs can be treated as APIs suitable for designing new antimicrobial agents and modifying therapies in controlling MDR pathogens.

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Section: Characterization Of Bacterial Levan Biosynthesized By Strept...mentioning

confidence: 75%

Elaboration of Nanostructured Levan-Based Colloid System as a Biological Alternative with Antimicrobial Activity for Applications in the Management of Pathogenic Microorganisms

Radenkovs,

Valdovska,

Galina

et al. 2023

Nanomaterials

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“…Because levan is formed by assembling fructose units produced by the hydrolysis of sucrose into glucose and fructose. Many authors (Gonzalez‑Garcinuno et al 45 , Hou et al 46 considered sucrose concentration as one of the factors controlling not only the production of levan but also its molecular weight. Levan production using sugarcane bagasse is very precious, as it helps recycle this waste into a valuable product.…”

Section: Resultsmentioning

confidence: 99%

Coculture of bacterial levans and evaluation of its anti-cancer activity against hepatocellular carcinoma cell lines

Wahab,

Shafey,

Mahrous

et al. 2024

Sci Rep

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This research represents a novel study to assess how coculture affects levan yield, structure, bioactivities, and molecular weight. Among the 16 honey isolates, four bacterial strains recorded the highest levan yield. The Plackett–Burman design showed that the coculture (M) of isolates G2 and K2 had the maximum levan yield (52 g/L) and the effective factors were sucrose, incubation time, and sugarcane bagasse. The CCD showed that the most proper concentrations for maximum levan yield (81 g/L): were 130 g/L of sucrose and 6 g/f of sugarcane bagasse. Levan’s backbone was characterized, and the molecular weight was determined. G2 and K2 isolates were identified based on 16 sRNA as Bacillus megaterium strain YM1C10 and Rhizobium sp. G6-1. M levan had promising antioxidant activity (99.66%), slowed the migration activity to a great extent, and recorded 70.70% inhibition against the hepatoblastoma cell line (HepG2) at 1000 µg/mL. Gene expression analysis in liver cancer cell lines (HePG2) revealed that M levan decreased the expression of CCL20), 2GRB2, and CCR6) genes and was superior to Doxo. While increasing the expression of the IL4R and IL-10 genes. The DNA damage values were significantly increased (P < 0.01) in treated liver cancer cell lines with levan M and Doxo. The results referred to the importance of each of the hydroxyl and carboxyl groups and the molecular weight in levans bioactivities.

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“…Taleb et al [ 36 ] also reported significantly different results and stated that levan production increased progressively as the pH values rose from 5.5 to 6.5, peaking at the initial pH of 6.5. Levan yield was shown by Hou et al [ 37 ] to be stable between pH 4 and 7.5, with Bacillus subtilis being used to provide the highest yield at pH 6.5. Fermentation was carried out at different temperatures ranging from 20 to 50 °C to study the influence of incubation temperature on levan biosynthesis.…”

Section: Discussionmentioning

confidence: 99%

Valorization of Using Agro-Wastes for Levan through Submerged Fermentation and Statistical Optimization of the Process Variables Applying Response Surface Methodology (RSM) Design

et al. 2023

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Levan is a homopolysaccharide of fructose units that repeat as its structural core. As an exopolysaccharide (EPS), it is produced by a great variety of microorganisms and a small number of plant species. The principal substrate used for levan production in industries, i.e., sucrose, is expensive and, hence, the manufacturing process requires an inexpensive substrate. As a result, the current research was designed to evaluate the potential of sucrose-rich fruit peels, i.e., mango peels, banana peels, apple peels, and sugarcane bagasse, to produce levan using Bacillus subtilis via submerged fermentation. After screening, the highest levan-producing substrate, mango peel, was used to optimize several process parameters (temperature, incubation time, pH, inoculum volume, and agitation speed) employing the central composite design (CCD) of response surface methodology (RSM), and their impact on levan production was assessed. After incubation for 64 h at 35 °C and pH 7.5, the addition of 2 mL of inoculum, and agitation at 180 rpm, the highest production of levan was 0.717 g/L of mango peel hydrolysate (obtained from 50 g of mango peels/liter of distilled water). The F-value of 50.53 and p-value 0.001 were calculated using the RSM statistical tool to verify that the planned model was highly significant. The selected model’s accuracy was proven by a high value (98.92%) of the coefficient of determination (R2). The results obtained from ANOVA made it clear that the influence of agitation speed alone on levan biosynthesis was statistically significant (p-value = 0.0001). The functional groups of levan produced were identified using FTIR (Fourier-transform ionization radiation). The sugars present in the levan were measured using HPLC and the levan was found to contain only fructose. The average molecular weight of the levan was 7.6 × 106 KDa. The findings revealed that levan can be efficiently produced by submerged fermentation using inexpensive substrate, i.e., fruit peels. Furthermore, these optimized cultural conditions can be applied on a commercial scale for industrial production and commercialization of levan.

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Factors affecting the production and molecular weight of levan in enzymatic synthesis by recombinant Bacillus subtilis levansucrase SacB‐T305A

Cited by 11 publications

References 31 publications

Elaboration of Nanostructured Levan-Based Colloid System as a Biological Alternative with Antimicrobial Activity for Applications in the Management of Pathogenic Microorganisms

Elaboration of Nanostructured Levan-Based Colloid System as a Biological Alternative with Antimicrobial Activity for Applications in the Management of Pathogenic Microorganisms

Coculture of bacterial levans and evaluation of its anti-cancer activity against hepatocellular carcinoma cell lines

Valorization of Using Agro-Wastes for Levan through Submerged Fermentation and Statistical Optimization of the Process Variables Applying Response Surface Methodology (RSM) Design

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