Optimization of Fermentation Medium for Extracellular Lipase Production from Aspergillus niger Using Response Surface Methodology

UV mutagenesis for lipase overproduction from Bacillus cereus ATA179, nutritional optimization, characterization and its usability in the detergent industry

In this study, the wild-type Bacillus cereus ATA179 was mutagenized by random UV mutagenesis to increase lipase production. The mutant with maximum lipolytic activity was named Bacillus cereus EV4. The mutant strain (10.6 U/mL at 24 h) produced 60% more enzyme than the wild strain (6.6 U/mL at 48 h). Nutritional factors on lipase production were investigated. Sucrose was the best carbon source, (NH4)2HPO4 was the best nitrogen source and CuSO4 was the best metal ion source. Mutant EV4 showed a 32% increase in lipase production in the modified medium. The optimum temperature and pH were found to be 60 °C and 7.0, respectively. CuSO4, CaCl2, LiSO4, KCl, BaCl2, and Tween 20 had an activating effect on the enzyme. Vmax and Km values were found to be 17.36 U/mL and 0.036 mM, respectively. The molecular weight was determined as 28.2 kDa. The activity of lipase was found to be stable up to 60 days at 20 °C, 75 days at 4 °C, and 90 days at -20 °C. The potential of lipase in the detergent industry was investigated. The enzyme was not affected by detergent additives but was effective in removing stains in fabrics contaminated with oily substances.

Preparation of Monascus-fermented ginkgo seeds: optimization of fermentation parameters and evaluation of bioactivity

In this study, a high monacolin K yield was achieved through solid-state fermentation of Ginkgo biloba seeds. Monascus purpureus suspension made from red yeast rice was used as spore inoculum. Fermentation conditions in solid-state fermentation were optimized using response surface methodology, and the optimal conditions for the maximum monacolin K yield (17.71 ± 1.57 mg/g) were 0.22% ammonium sulfate, 0.34% ammonium chloride, 0.05% magnesium sulfate, fermentation time of 12 days, inoculation volume of 11%, and temperature of 27 °C. The total phenolic content of Monascus-fermented ginkgo seeds attained 9.67 mg GAE/g, 4.88-fold higher than that of unfermented ginkgo seeds. The scavenging abilities of DPPH and ABTS free radicals increased to 9.79 mg TE/g and 13.92 mg TE/g, respectively. These findings highlight the importance of investigating the optimal fermentation conditions for maximum monacolin K yield and the utilization value of ginkgo seed as fermentation substrate for higher bioactivities.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10068-022-01078-z.

Investigation of Lipolytic-Secreting Bacteria from an Artificially Polluted Soil Using a Modified Culture Method and Optimization of Their Lipase Production

Compared to lipases from plants or animals, microbial lipases play a vital role in different industrial applications and biotechnological perspectives due to their high stability and cost-effectiveness. Therefore, numerous lipase producers have been investigated in a variety of environments in the presence of lipidic carbon and organic nitrogen sources. As a step in the development of cultivating the unculturable functional bacteria in this study, the forest soil collected from the surrounding plant roots was used to create an artificially contaminated environment for lipase-producing bacterial isolation. The ten strongest active bacterial strains were tested in an enzyme assay supplemented with metal ions such as Ca2+, Zn2+, Cu2+, Fe2+, Mg2+, K+, Co2+, Mn2+, and Sn2+ to determine bacterial tolerance and the effect of these metal ions on enzyme activity. Lipolytic bacteria in this study tended to grow and achieved a high lipase activity at temperatures of 35-40 °C and at pH 6-7, reaching a peak of 480 U/mL and 420 U/mL produced by Lysinibacillus PL33 and Lysinibacillus PL35, respectively. These potential lipase-producing bacteria are excellent candidates for large-scale applications in the future.

Production strategies and biotechnological relevance of microbial lipases: a review

Lipases are enzymes that catalyze the breakdown of lipids into long-chain fatty acids and glycerol in oil-water interface. In addition, they catalyze broad spectrum of bioconversion reactions including esterification, inter-esterification, among others in non-aqueous and micro-aqueous milieu. Lipases are universally produced from plants, animals, and microorganisms. However, lipases from microbial origin are mostly preferred owing to their lower production costs, ease of genetic manipulation etc. The secretion of these biocatalysts by microorganisms is influenced by nutritional and physicochemical parameters. Optimization of the bioprocess parameters enhanced lipase production. In addition, microbial lipases have gained intensified attention for a wide range of applications in food, detergent, and cosmetics industries as well as in environmental bioremediation. This review provides insights into strategies for production of microbial lipases for potential biotechnological applications.

Production, purification, characterization, and biological properties of Rhodosporidium paludigenum polysaccharide

The yield of marine red yeast polysaccharide (MRYP) obtained from Rhodosporidium paludigenum was increased by optimizing fermentation conditions, and the pure polysaccharide was extracted by column chromatography. The molecular weight of pure MRYP and the ratio of mannose to glucose in components of MRYP were determined. Antioxidant and antibacterial abilities of MRYP were investigated in vitro and in vivo. The optimal fermentation parameters were as follows: Medium 4, pH = 6.72, temperature = 30.18°C, blades speed = 461.36 r/min; the optimized yield reached 4323.90 mg/L, which was 1.31 times the original yield. The sequence of factors that affected the MRYP yield was the blades speed>pH>temperature. The main components of MRYP were MYH-1 and MYH-2. The molecular weights of MYH-1 and MYH-2 were 246.92 kDa and 21.88 kDa, respectively; they accounted for 53.60% and 28.75% of total polysaccharide. In MYH-1 and MYH-2, the proportion of glucose and mannose accounted for 46.94%, 38.46%, and 67.10%, 7.17%, respectively. In vitro, the ability of scavenging DPPH•, •OH, and •O2− radical was 32.26%, 24.34%, and 22.09%; the minimum inhibitory concentration (MIC) of MRYP was 480 μg/mg. In vivo, MRYP improved the lambs’ body weight, antioxidant enzyme activity, and the number of probiotics, but it reduced the feed/gain (F/G) ratio and the number of pathogenic bacteria in 60-days-old lambs.

The use of response surface methodology for enhanced production of a thermostable bacterial lipase in a novel yeast system

A thermostable bacterial lipase from Geobacillus zalihae was expressed in a novel yeast Pichia sp. strain SO. The preliminary expression was too low and discourages industrial production. This study sought to investigate the optimum conditions for T1 lipase production in Pichia sp. strain SO. Seven medium conditions were investigated and optimized using Response Surface Methodology (RSM). Five responding conditions namely; temperature, inoculum size, incubation time, culture volume and agitation speed observed through Plackett-Burman Design (PBD) method had a significant effect on T1 lipase production. The medium conditions were optimized using Box-Behnken Design (BBD). Investigations reveal that the optimum conditions for T1 lipase production and Biomass concentration (OD₆₀₀) were; Temperature 31.76 °C, incubation time 39.33 h, culture volume 132.19 mL, inoculum size 3.64%, and agitation speed of 288.2 rpm with a 95% PI low as; 12.41 U/mL and 95% PI high of 13.65 U/mL with an OD₆₀₀ of; 95% PI low as; 19.62 and 95% PI high as; 22.62 as generated by the software was also validated. These predicted parameters were investigated experimentally and the experimental result for lipase activity observed was 13.72 U/mL with an OD₆₀₀ of 24.5. At these optimum conditions, there was a 3-fold increase on T1 lipase activity. This study is the first to develop a statistical model for T1 lipase production and biomass concentration in Pichia sp. Strain SO. The optimized production of T1 lipase presents a choice for its industrial application.

Enhancement of Aeribacillus pallidus strain VP3 lipase catalytic activity through optimization of medium composition using Box-Behnken design and its application in detergent formulations

Lipases are hydrolytic enzymes owing much importance in industrial applications. These enzyme-based detergents are ecofriendly and produce a wastewater with low level of COD (chemical oxygen demand). In the present work, a novel halophilous, thermoalkaline, and detergent-tolerant lipase produced by a newly isolated Aeribacillus pallidus strain VP3 was studied. Considerable interest has been given to this lipase by the improvement of its catalytic activity through the optimization of the pH, the (C/N) ratio, and the inoculum size, using the response surface methodology based on the Box-Behnken design of experiments. A total of 16 experiments were conducted, and the optimized pH, (C/N) ratio, and inoculum size were 10, 1, and 0.3, respectively. The results of the analysis of variance (ANOVA) test indicated that the established model was significant (p value < 0.05). The optimization of the production conditions leads to 2.83-fold of increase in the catalytic activity calculated as the ratio of the activity obtained after optimization (68 U) and the initial activity before optimization (24 U). All in all, the lipase of Aeribacillus pallidus could be considered as a potential candidate to be incorporated in detergent formulations since it shows a good stability towards detergents and wash performance.

Lunasin abrogates the expression of matrix metalloproteinases and reduction of type II collagen

Impairment of type II collagen caused by MMPs in response to overproduction of IL-1β is an important step in the pathological progression of osteoarthritis (OA). Lunasin, a well-known peptide present in the soybean, has displayed a positive impact on numerous physiological functions. Little information in the effects of lunasin on cartilage degradation has been sought in clinical research before. Here, we report that lunasin suppressed the increase in MMP-3 and MMP-13 caused by IL-1β. In addition, we found that lunasin could prevent the decrease in TIMP-1 and TIMP-2 expressions caused by IL-1β. Notably, lunasin suppressed reduction of type II collagen, the basis for articular cartilage. Lunasin also attenuated activation of the JAK2/STAT1/IRF-1 pathway. These effects of lunasin suggest that it might become a promising therapeutic agent for chondro-protective therapy.

Optimization of submerged culture conditions involving a developed fine powder solid seed for exopolysaccharide production by the medicinal mushroom Ganoderma lucidum

To facilitate Ganoderma lucidum submerged cultivation and achieve high productivity, four fine powder solid substrates incorporated with different nitrogen-rich supplements were utilized to grow the fungus and as solid seed for its submerged culture. Of the four solid seeds, the soybean meal solid seed gave the highest biomass (10.73 g/L) and exopolysaccharide (EPS) (1.22 g/L), higher than those (8.36 g/L biomass and 0.44 g/L EPS) obtained with mycelial liquid seed. The optimal level of soybean meal supplementation was 20% (w/w) for production of the solid seed. Following single factor experiments, levels of three selected process variables were optimized as: the moisture content of solid seed, 70%; inoculum size, 0.8 g/flask; and rotary speed, 160 rpm. These conditions were validated experimentally with improved EPS yield of 1.33 g/L. The developed solid seed can be conveniently used for G. lucidum submerged culture with improved EPS productivity.

Optimization of Submerged Fermentation Medium for Matrine Production by Aspergillus terreus, an Endophytic Fungus Harboring Seeds of Sophora flavescens, Using Response Surface Methodology

Different endophytes isolated from the seeds of Sophora flavescens were tested for their ability to produce matrine production. Response surface methodology (RSM) was applied to optimize the medium components for the endophytic fungus. Results indicated that endophyte Aspergillus terreus had the ability to produce matrine. The single factor tests demonstrated that potato starch was the best carbon source and the combination of peptone and NH₄NO₃ was the optimal nitrogen source for A. terreus. The model of RSM predicted to gain the maximal matrine production at 20.67 µg/L, when the potato starch was 160.68 g/L, peptone was 24.96 g/L and NH₄NO₃ was 2.11 g/L. When cultured in the optimal medium, the matrine yield was an average of 20.63 ± 0.11 µg/L, which was consistent with the model prediction. This study offered an alternative source for the matrine production by endophytic fungus fermentation and may have far-reaching prospect and value.