Lipase production by Penicillium restrictum in a bench-scale fermenter : effect of carbon and nitrogen nutrition, agitation, and aeration

Homoscleromorpha-derived Bacillus spp. as potential sources of biotechnologically-relevant hydrolases and biosurfactants

Despite hydrolytic exoenzymes and biosurfactants having been gradually reported from the poriferan microbiome, little is known about these bioproducts in microorganisms inhabiting Homoscleromorpha sponges. Here, we investigated the production of hydrolases and biosurfactants in bacteria isolated from three shallow-water homoscleromorph species, Oscarella sp., Plakina cyanorosea, and Plakina cabofriense. A total of 99 of 107 sponge-associated bacterial isolates exhibited activity for at least one of the analyzed hydrolases. Following fermentation in Luria-Bertani (LB) and Tryptic Soy Broth (TSB), two isolates, 80BH11 and 80B1:1010b, showed higher lipase and peptidase activities. Both of them belonged to the Bacillus genus and were isolated from Oscarella. Central composite design leveraged up the peptidase activity in 280% by Bacillus sp. 80BH11 in the TSB medium for 48 h at 30 °C. The optimized model also revealed that pH 6.5 and 45 °C were the best conditions for peptidase reaction. In addition, Bacillus sp. 80BH11 was able to release highly emulsifying and remarkably stable surfactants in the LB medium. Surfactin was finally elucidated as the biosurfactant generated by this sponge-derived Bacillus. In conclusion, we hope to have set the scenery for further prospecting of industrial enzymes and biosurfactants in Homoscleromorpha microbiomes.

Production of new lipase from Preussia africana and partial characterization

The present work aims to study the production of a new extracellular lipase from the endophytic fungus Preussia africana isolated from red lapacho tree (Handroanthus impetiginosus). Tests were carried out in order to evaluate the influence of different inducing oils (sunflower, cotton, corn, palm kernel, canola and linseed) and carbon/nitrogen ratio (C/N of 11.73, 8.63 and 7.05) on submerged fermentation aiming at optimal production of a single extracellular lipase. Results show that an optimal lipase production of 14.5 kDa has been attained after 48 h of fermentation when sunflower oil was used in the C/N ratio of 8.63 in the fermentation medium. The produced lipase showed greater activity for oils that had higher percentage of unsaturated fatty acids in their composition. Characterization was performed using a two-factor central composite rotatable design (CCRD), and the pH 6 was found to be optimal (around 28 U/mL). The temperature range studied (from 20 to 54 °C) showed no difference for the lipase catalytic activity. This is an advantage, especially when aiming at its application in reactions of industrial interest.

Fungal and enzymatic bio-depolymerization of waste post-consumer poly(ethylene terephthalate) (PET) bottles using Penicillium species

Poly(ethylene terephthalate) (PET) is a petroleum-based plastic that is massively produced and used worldwide. A promising PET recycling process to circumvent petroleum feedstock consumption and help to reduce environmental pollution is microbial or enzymatic biodegradation of post-consumer (PC) PET packages to its monomers-terephthalic acid (TPA) and ethylene glycol (EG)-or to key intermediates in PET synthesis-such as mono- and bis-(2-hydroxyethyl) terephthalate (MHET and BHET). Two species of filamentous fungi previously characterized as lipase producers (Penicillium restrictum and P. simplicissimum) were evaluated in submerged fermentation for induction of lipase production by two inducers (BHET and amorphous PET), and for biodegradation of two substrates (BHET and PC-PET). BHET induced lipase production in P. simplicissimum, achieving a peak of 606.4 U/L at 49 h (12.38 U/L.h), representing an almost twofold increase in comparison to the highest peak in the control (without inducers). Microbial biodegradation by P. simplicissimum after 28 days led to a 3.09% mass loss on PC-PET fragments. In contrast, enzymatic PC-PET depolymerization by cell-free filtrates from a P. simplicissimum culture resulted in low concentrations of BHET, MHET and TPA (up to 9.51 µmol/L), suggesting that there are mechanisms at the organism level that enhance biodegradation. Enzymatic BHET hydrolysis revealed that P. simplicissimum extracellular enzymes catalyze the release of MHET as the predominant product. Our results show that P. simplicissimum is a promising biodegrader of PC-PET that can be further explored for monomer recovery in the context of feedstock recycling processes.

Improved production of biocatalysts by Yarrowia lipolytica using natural sources of the biopolyesters cutin and suberin, and their application in hydrolysis of poly (ethylene terephthalate) (PET)

Since plastic pollution emerged as an urgent environmental problem, different biocatalysts have been tested for poly(ethylene terephthalate) (PET) hydrolysis. This work evaluated three different possible inducers for lipases and/or esterases, two natural sources of biopolymers (apple peels and commercial cork) and PET, as supplements in the solid-state fermentation of soybean bran by Yarrowia lipolytica. The obtained enzymatic extracts displaying different levels of lipase and esterase activities were then tested for PET depolymerization. Supplementation with 5 or 20 wt% of commercial cork led to an increase of 16% in lipase activity and to an increase of 131% in esterase activity, respectively. PET supplementation also led to an increase in the esterase activity of the enzymatic extracts (up to 69%). Enzymes produced in the screening step were able to act as biocatalysts in PET hydrolysis. Enzymatic extracts obtained in fermentation samples supplemented with 20 wt% PET and 20 wt% apple peels led to the highest terephthalic acid concentration (21.2 µmol L^-1) in 7 days, whereas enzymes produced in commercial cork media were more efficient for bis(2-hydroxyethyl) terephthalate (BHET) hydrolysis, one of the key-PET hydrolysis intermediates. Results suggest a good potential of the biocatalysts produced by Y. lipolytica IMUFRJ 50,682 in a low-cost media for subsequent utilization in PET depolymerization reactions. This is one of the few reports on the use of a yeast for this application.

Increase of Candida antarctica lipase B production under PGK promoter in Pichia pastoris: effect of multicopies

The effect of gene dosage on the production of Candida antarctica lipase B (CalB) in the methylotrophic yeast Komagataella phaffii, at high densities in a simple medium containing crude glycerin as the sole carbon source, is described. The use of crude glycerin, the main by-product of biodiesel production from vegetable oils, will reduce the production cost of the bioprocess. Two K. phaffii strains were constructed with one or three copies of LipB, an optimized version of the gene encoding CalB under the control of the constitutive P_PGK1 promoter. These two constructs were tested and compared on batches using minimal-salts medium with crude glycerin. The strain with three copies achieved a higher enzyme yield (48,760 U/L, 2.3-fold higher than the one-copy strain), with 42 g/L biomass, with no effects on growth.

Obtaining filamentous fungi and lipases from sewage treatment plant residue for fat degradation in anaerobic reactors

A residue from the primary treatment of a Wastewater Treatment Plant (WWTP) was used to isolate filamentous fungi with lipase production potential. Two of the 27 isolated fungi presented high hydrolysis index and were selected for lipase production by solid-state fermentation (SSF). The fermentations were conducted at 30 °C for 48 h, with moist air circulation, using 20% (w/w) of the residue mixture with a basal medium (agroindustrial residue-babassu cake), obtaining a solid enzymatic preparation (SEP) with lipase activity of 19 U/g with the fungus identified as Aspergillus terreus. Scum, collected in an anaerobic reactor operating in a WWTP, was hydrolyzed with SEP and subjected to anaerobic biodegradability tests at 30 °C. Different dilutions of crude (Control) or hydrolyzed scum in raw sewage were evaluated. The dilution of 5% (v/v) of hydrolyzed scum in raw sewage proved the most adequate, as it resulted in higher methane yield compared to the raw sewage (196 and 133 mL CH4/g CODadded, respectively), without increasing the chemical oxygen demand (COD) of the treated sewage (138 and 134 mg/L). The enzymatic hydrolysis of the scum, followed by dilution in the influent sewage, is technically feasible and increases methane production in anaerobic reactors.

A halotolerant thermostable lipase from the marine bacterium Oceanobacillus sp. PUMB02 with an ability to disrupt bacterial biofilms

A halotolerant thermostable lipase was purified and characterized from the marine bacterium Oceanobacillus sp. PUMB02. This lipase displayed a high degree of stability over a wide range of conditions including pH, salinity, and temperature. It was optimally active at 30 °C and pH 8.0 respectively and was stable at higher temperatures (50-70 °C) and alkaline pH. The molecular mass of the lipase was approximately 31 kDa based on SDS-PAGE and MALDI-ToF fingerprint analysis. Conditions for enhanced production of lipase by Oceanobacillus sp. PUMB02 were attained in response surface method-guided optimization with factors such as olive oil, sucrose, potassium chromate, and NaCl being evaluated, resulting in levels of 58.84 U/ml being achieved. The biofilm disruption potential of the PUMB02 lipase was evaluated and compared with a marine sponge metagenome derived halotolerant lipase Lpc53E1. Good biofilm disruption activity was observed with both lipases against potential food pathogens such as Bacillus cereus MTCC1272, Listeria sp. MTCC1143, Serratia sp. MTCC4822, Escherichia coli MTCC443, Pseudomonas fluorescens MTCC1748, and Vibrio parahemolyticus MTCC459. Phase contrast microscopy, scanning electron microscopy, and confocal laser scanning microscopy showed very effective disruption of pathogenic biofilms. This study reveals that marine derived hydrolytic enzymes such as lipases may have potential utility in inhibiting biofilm formation in a food processing environment and is the first report of the potential application of lipases from the genus Oceanobacillus in biofilm disruption strategies.

Application of Plackett-Burman Experimental Design for Lipase Production by Aspergillus niger Using Shea Butter Cake

Plackett-Burman design was used to efficiently select important medium components affecting the lipase production by Aspergillus niger using shea butter cake as the main substrate. Out of the eleven medium components screened, six comprising of sucrose, (NH₄)₂SO₄, Na₂HPO₄, MgSO₄, Tween-80, and olive oil were found to contribute positively to the overall lipase production with a maximum production of 3.35 U/g. Influence of tween-80 on lipase production was investigated, and 1.0% (v/w) of tween-80 resulted in maximum lipase production of 6.10 U/g. Thus, the statistical approach employed in this study allows for rapid identification of important medium parameters affecting the lipase production, and further statistical optimization of medium and process parameters can be explored using response surface methodology.

The Use of Response Surface Methodology as a Statistical Tool for Media Optimization in Lipase Production from the Dairy Effluent Isolate Fusarium solani

The optimization of extracellular lipase production by Fusarium isolani strain SKWF7 isolated from dairy wastewater was carried out in this study. Initially, the physicochemical factors significantly influencing enzyme production were studied by varying one-factor-at-a-time (OFAT). A mesophilic temperature of 40°C, alkaline pH of 8, and incubation period of 72 hours were found to be the optimal conditions for lipase production. Among the media components, the disaccharide sucrose acted as the best carbon source; palm oil as the best inducing lipid substrate; casein and (NH4)2SO4 as the best organic and inorganic nitrogen sources; Ca(2+) ion as the best trace element. In the next phase of work, statistical optimization of medium components was performed by employing the Box-Behnken design of Response Surface Methodology (RSM). The optimum concentrations of three significant factors, namely, palm oil, (NH4)2SO4, and CaCO3 were determined by this method to be 5% (v/v), 5.5 g/L, and 0.1 g/L, respectively. RSM-guided design of experiments resulted in a maximum lipase production of 73.3 U/ml, which is a 1.7-fold increase in comparison with that obtained in the unoptimized medium. These results point towards the success of the model in developing a process for the production of lipase, an enzyme of enormous industrial significance.

Adding value to a toxic residue from the biodiesel industry: production of two distinct pool of lipases from Penicillium simplicissimum in castor bean waste

In countries with a strong agricultural base, such as Brazil, the generation of solid residues is very high. In some cases, these wastes present no utility due to their toxic and allergenic compounds, and so are an environmental concern. The castor bean (Ricinus communis) is a promising candidate for biodiesel production. From the biodiesel production process developed in the Petrobras Research Center using castor bean seeds, a toxic and alkaline waste is produced. The use of agroindustrial wastes in solid-state fermentation (SSF) is a very interesting alternative for obtaining enzymes at low cost. Therefore, in this work, castor bean waste was used, without any treatment, as a culture medium for fungal growth and lipase production. The fungus Penicillium simplicissimum was able to grow and produce an enzyme in this waste. In order to maximize the enzyme production, two sequential designs-Plackett-Burman (variable screening) followed by central composite rotatable design (CCRD)-were carried out, attaining a considerable increase in lipase production, reaching an activity of 155.0 U/g after 96 h of fermentation. The use of experimental design strategy was efficient, leading to an increase of 340% in the lipase production. Zymography showed the presence of different lipases in the crude extract. The partial characterization of such extract showed the occurrence of two lipase pools with distinct characteristics of pH and temperature of action: one group with optimal action at pH 6.5 and 45°C and another one at pH 9.0 and 25°C. These results demonstrate how to add value to a toxic and worthless residue through the production of lipases with distinct characteristics. This pool of enzymes, produced through a low cost methodology, can be applied in different areas of biotechnology.

Production of extracellular lipases by Rhizopus oligosporus in a stirred fermentor

The present investigation deals with the kinetics of submerged extracellular lipases fermentation by both wild and mutant strains of Rhizopus oligosporus var.microsporus in a laboratory scale stirred fermentor. Other parameters studied were inoculum size, pH, agitation and rate of aeration. It was found that the growth and lipases production was increased gradually and reached its maximum 9.07± 0.42(a) U mL(-1) (W) and 42.49 ± 3.91(a) U mL(-1) (M) after 30h of fermentation for both wild and mutant strain. There is overall increase of 109% (W) and 124% (M) in the production of extracellular lipases as compared to shake flask. Another significant finding of the present study is that the fermentation period is reduced to 30 h in case of wild and 23 h in case of mutant from 48 h in shake flask studies. The specific productivity of mutant strain (qp = 377.3 U/g cells/h) was several folds higher than wild strain. The specific production rate and growth coefficient revealed the hyperproducibility of extracellular lipases using mutant IIB-63NTG-7.