Improved production of tannase by Klebsiella pneumoniae using Indian gooseberry leaves under submerged fermentation using Taguchi approach

Production of tannase from a newly isolated yeast, Geotrichum cucujoidarum using agro-residues

With an aim of producing commercially important tannase enzyme using cheap and readily available agro-residues, leaves of Indian Gooseberry (Phyllanthus emblica) and Jamun (Syzygium cumini), peels of Lemon (Citrus limon), and Pomegranate (Punica granatum) were screened. Newly isolated Geotrichum cucujoidarum was utilized for the study. Preliminary studies indicated that tannase titer obtained is not proportional to the tannin content of the agro-residues and solid state fermentation superior compared to submerged fermentation. Jamun mixed with lemon peel in equal proportion supplemented with minerals under solid-state fermentation gave a tannase titer of 15.46 U/g dry solids. Through successful implantation of Plackett-Burman design, yeast extract concentration, inoculum volume, and amount of substrate were found to be the most significant factors. Further optimization of these three factors through Response Surface Methodology resulted in the 1.7-fold increase in tannase titer. Validation experiments using 3.97 g of Jamun leaves + lemon peel powder mixed with a nutrient solution having (w/v) yeast extract - 1.1%, dextrose - 3%, Urea - 1.125%, potassium chloride - 0.1%, magnesium sulfate heptahydrate - 0.1% with the initial pH of 5, inoculated with 2.48 ml of inoculum gave a tannase titer of 26.43 U/g dry solids after 6 days of solid-state fermentation.

Optimum Fermentation Conditions for Bovine Lactoferricin-Lactoferrampin-Encoding LimosiLactobacillus reuteri and Regulation of Intestinal Inflammation

The multifunctional antibacterial peptide lactoferricin-lactoferrampin (LFCA) is derived from bovine lactoferrin. Optimization of the fermentation process should be studied since different microorganisms have their own favorable conditions and processes for growth and the production of metabolites. In this study, the culture conditions of a recombinant strain, pPG-LFCA-E/LR-CO21 (LR-LFCA), expressing LFCA was optimized, utilizing the high-density fermentation process to augment the biomass of LimosiLactobacillus reuteri and the expression of LFCA. Furthermore, an assessment of the protective effect of LR-LFCA on intestinal inflammation induced by lipopolysaccharide (LPS) was conducted to evaluate the impact of LR-LFCA on the disease resistance of piglets. The findings of this study indicate that LR-LFCA fermentation conditions optimally include 2% inoculation volume, 36.5 °C fermentation temperature, 9% dissolved oxygen concentration, 200 revolutions/minute stirring speed, pH 6, 10 mL/h glucose flow, and 50% glucose concentration. The inclusion of fermented LR-LFCA in the diet resulted in an elevation of immunoglobulin levels, significant upregulation of tight junction proteins ZO-1 and occludin, reinforcement of the intestinal barrier function, and significant amelioration of the aberrant alterations in blood physiological parameters induced by LPS. These results offer a theoretical framework for the implementation of this micro-ecological preparation in the field of piglet production to enhance intestinal well-being.

Production, Purification and Characterization of Extracellular Tannase from a Newly Isolated Yeast, Geotrichum cucujoidarum

With an aim to isolate a tannase positive organism, the microbial mat growing on the stored areca extract leachate surface was screened. Once the tannase positive organism was isolated, it was identified by ITS/18S rRNA gene sequencing. Further, the enzyme was purified and examined for its biochemical properties. A potent extracellular tannase-producing yeast was isolated and was identified as Geotrichum cucujoidarum. After the shake flask studies, the enzyme activity of 4.42 U/ml and specific activity of 29.86 U/mg were achieved in a medium with tannic acid as an inducer. Later, ethanol (70%) precipitation followed by purification through FPLC using SEC 650 column resulted in 166.37 U/mg specific activity and a recovery of 50.54%. The purified enzyme was a monomer with a molecular weight of 63 kDa. The optimum pH and the temperature of the enzyme were found to be 5.0 and 30°C, respectively. The Michaelis-Menten constant (Km) was found to be 2.9 mM, and the turn over number (kcat) and catalytic efficiency (kcat/km) of the purified tannase were 102 S-1 and 35.17 mM-1S-1 respectively. Temperature and pH stability profiles of the enzyme, influence of various metal ions, chelators and surfactants on enzyme activity and kinetic constants of enzyme shows that the tannase produced from Geotrichum cucujoidarum is unique and is a potential candidate for further studies.

Characterization of Apple Juice Clarified by Tannase from Serratia marcescens IMBL5 Produced using Agro-industrial Waste Materials

In the present study, clarification of apple juice with tannase from S. marcescens IMBL5 produced using various agro-waste materials was carried out. Sugarcane bagasse was found to be the most suitable source for the augmented production of tannase enzyme by response surface methodology with the temperature at 40 °C, pH 4.5 and the incubation period of 96 hrs. The enzyme was quantified and partially purified through protein precipitation. The partially purified tannase with gelatin clarified about 62% of the apple juice in 3 hr of incubation at room temperature and it was gently increased with the incubation period. The detannification was characterized by estimating tannin content of the clarified juice. The amount of total reducing sugar in the juice was increased almost 50 % after 5 hours of incubation period. FTIR spectrum of the clarified juice revealed that the conformational changes that occurred in the functional groups. The spectrum absorptions between 500 and 1700 cm-1 mainly reflected the C=O stretch of the pectins and acids and C–O modes of the carbohydrates that correspond to the absorption zones of the sugars. The HPLC analysis of the clarified apple juice indicate the presence of phenolic compounds and sugar derivatives such as gallic acid, catechin, caffeic acid, epicatechin, glucose and sucrose which confirms the quality and clarity of the apple juice using the tannase enzyme.

Taguchi optimization and scale up of xylanase from Bacillus licheniformis isolated from hot water geyser

BACKGROUND

Xylanase is one of the widely applied industrial enzymes with diverse applications. Thermostability and alkali tolerance are the two most desirable qualities for industrial applications of xylanase. In this paper, we reveal the statistical Taguchi optimization strategy for maximization of xylanase production. The important process parameters pH, temperature, concentration of wheat bran, and concentration of yeast extract were optimized using the Taguchi L8 orthogonal array where the 4 factors were considered at 2 levels (high and low).

RESULTS

The optimized conditions given by model were obtained as follows: (i) pH 6, (ii) culture temperature 35 °C, (iii) concentration of xylan 2% w/v, (iv) concentration of wheat bran 2.5% w/v. The production was scaled upto 2.5 L bioreactor using optimized process parameters. A high xylanase titer of 400 U/ml could be achieved in less than 60 h of culture in the reactor.

CONCLUSION

Optimization was successful in achieving about threefold increase in the yield of xylanase. The optimized conditions resulted in a successful scale up and enhancement of xylanase production.

Optimization of glutaminase-free L-asparaginase production using mangrove endophytic Lysinibacillus fusiformis B27

Background: The mangrove, Rhizophora mucronata, an essential source of endophytic bacteria, was investigated for its ability to produce glutaminase-free L-asparaginase. The study aimed to obtain glutaminase-free L-asparaginase-producing endophytic bacteria from the mangrove and to optimize enzyme production.

Methods: The screening of L-asparaginase-producing bacteria used modified M9 medium. The potential producer was further analyzed with respect to its species using 16S rRNA gene sequencing. Taguchi experimental design was applied to optimize the enzyme production. Four factors (L-asparagine concentration, pH, temperature, and inoculum concentration) were selected at four levels.

Results: The results indicated that the endophytic bacteria Lysinibacillus fusiformis B27 isolated from R. mucronata was a potential producer of glutaminase-free L-asparaginase. The experiment indicated that pH 6, temperature at 35°C, and inoculum concentration of 1.5% enabled the best production and were essential factors. L-asparagine (2%) was less critical for optimum production.

Conclusions: L. fusiformis B27, isolated from Rhizophora mucronata, can be optimized for L-ASNase enzyme production using optimization factors (L-ASNase, pH, temperature, and inoculum), which can increase L-ASNase enzyme production by approximately three-fold.

Solid state fermentation of Bacillus gottheilii M2S2 in laboratory-scale packed bed reactor for tannase production

Production of tannase was performed in packed bed reactor filled with an inert support polyurethane foam (PUF) using Bacillus gottheilii M2S2. The influence of process parameters such as fermentation time (24-72 h), tannic acid concentration (0.5-2.5% w/v), inoculum size (7-12% v/v), and aeration rate (0-0.2 L/min) on tannase production with PUF were analyzed using one variable at a time (OVAT) approach. The outcome of OVAT was optimized by central composite design. Based on the statistical investigation, the proposed mathematical model recommends 1% (w/v) of tannic acid, 10% (v/v) of inoculum size and 0.13 L/min of aeration rate for maximum production (76.57 ± 1.25 U/L). The crude enzyme was purified using ammonium sulfate salt precipitation method followed by dialysis. The biochemical properties of partially purified tannase were analyzed and found the optimum pH (4.0), temperature (40 °C) for activity, and K_m (1.077 mM) and V_max (1.11 µM/min) with methyl gallate as a substrate. Based on the SDS-PAGE analysis, tannase exhibited two bands with molecular weights of 57.5 and 42.3 kDa. Briefly, the partially purified tannase showed 4.2 fold increase (63 ± 1.60 U/L) in comparison to the submerged fermentation and the production of tannase was validated by using NMR spectrometer.

Application of response surface methodology for optimization of medium components for the production of secondary metabolites by Streptomyces diastatochromogenes KX852460

A bioactive strain Streptomyces diastatochromogenes KX852460 was selected for the production of secondary metabolites to control the target spot disease on tobacco leaves, caused by the Rhizoctonia solani AG-3. Peanut meal, soluble starch, NaCl, yeast extract, and ammonium sulphate were identified the best ingredient for high antifungal activity of S. diastatochromogenes KX852460 against the R. solani AG-3. For the improved production of secondary metabolites, central composite design of response surface methodology was applied in submerged fermentation. The best concentrations of ingredients were peanut meal 4.88%, soluble starch 4.40%, NaCl 0.52%, yeast extract 0.47%, and ammonium sulphate 0.0360%. Study of metabolism changes in the submerged fermentation process was analyzed. Level of the reducing sugar increased, as the total sugar consumed. Amino nitrogen and total sugar decrease tendency, which indicated the growth of bacteria in submerged fermentation batch. Production of secondary and other metabolites influenced the pH of the fermentation batch.

Optimization and partial characterization of intracellular anticandidal protein from Aspergillus giganteus MTCC 8408 using taguchi DOE

A new intracellular antifungal protein (afp) production with average molecular weight 24.3 kDa and yield of 0.65 ± 0.1 mg/gram dry cell weight (gdcw) of mycelia in submerged fermentation of Aspergillus giganteus MTCC 8408 was optimized. Taguchi's DOE (design of experiment) L₂₇ orthogonal array (OA) was constructed using Qualitek-4 software with 8 most influensive factors namely, culture pH, temperature, slant age, inoculum volume, agitation and KH₂PO₄. Scanning electron microscopy (SEM) was used to correlate the effect of selected factors on fungal cell morphology and afp production. The crude protein purification was accomplished using pure ammonium sulfate fractionation followed by carboxymethyl cellulose (CMC) ion-exchange chromatography and sephadex G-100 gel filtration. The average molecular mass of the purified protein was figured by silver stained SDS (sodium dodecylsulphate)-PAGE (poly-acryl amide gel electrophoresis). In vitro antifungal susceptibility assay was profiled against Candida albicans NCIM 3471 and minimum inhibitory concentrations (MICs) were in the range 3 to 4 µg/ml. Characterization of protein was observed with FTIR (Fourier transform infrared spectroscopy) analysis. The optimal production condition for crude afp was obtained as follows: soluble starch: 20 g/l; Corn steep liquor (CSL, 2%) + proteose peptone (PP, 1%): 30 g/l; pH: 5.8; temperature: 25°C; slant age: 3 d; inoculum size: 5% (v/v); agitation: 180 rpm; KH₂PO₄: 0.1 g/l. The validation experiments using optimized conditions confirmed an improvement in afp production by 59.4% against the expected enhancement of afp production by 61.22%. The present statistical optimization study revealed an opportunity to promote economical design at the industrial level for future scale up of effective antifungal agent against opportunistic oral and vaginal infection.

Production of Enzymes From Agricultural Wastes and Their Potential Industrial Applications

Enzymatic hydrolysis is the significant technique for the conversion of agricultural wastes into valuable products. Agroindustrial wastes such as rice bran, wheat bran, wheat straw, sugarcane bagasse, and corncob are cheapest and plentifully available natural carbon sources for the production of industrially important enzymes. Innumerable enzymes that have numerous applications in industrial processes for food, drug, textile, and dye use have been produced from different types of microorganisms from agricultural wastes. Utilization of agricultural wastes offers great potential for reducing the production cost and increasing the use of enzymes for industrial purposes. This chapter focuses on economic production of actinobacterial enzymes from agricultural wastes to make a better alternative for utilization of biomass generated in million tons as waste annually.