Characterization of biotechnologically relevant extracellular lipase produced by Aspergillus terreus NCFT 4269.10

Characterization and Enzymatic Potential of Bacteria and Fungi From Mwakirunge Dumpsite, Kenya

Accumulation of solid waste is a major global challenge. The conventional waste disposal methods are often ineffective in mitigating solid waste pollution, highlighting the need for other sustainable alternatives. This study is aimed at isolating and identifying potential waste-degrading microorganisms from Mwakirunge dumpsite in Mombasa, Kenya. A total of 16 soil samples were collected using a randomized block design. The samples were inoculated in enriched basal media containing mixed municipal solid waste and incubated at 37°C for 21 days. Microbial identification was conducted using standard morphological, biochemical, and molecular approaches. DNA was extracted using organic isolation methods, and PCR amplification of the 16S rRNA gene for bacteria and the ITS gene for fungi was performed. Phylogenetic analysis grouped bacterial isolates into phylum Bacillota (Firmicutes), Pseudomonadota (Proteobacteria), and Actinomycetota (Actinobacteria) that included members of the genera bacilli, Pseudomonas, brevibacilli, Microbacterium, Ochrobactrum, Paenibacillus, Staphylococcus, Isoptericola, and Streptomyces. Fungal isolates belonged to the genus Aspergillus within the phylum Ascomycota. Three bacterial isolates B4S2 b (MZ571886), B3S1 (MZ571907), and B3S4 B (MZ571915) and one fungal isolate B2S2 a1 (MZ569413) had low sequence similarities with their closely known taxonomic relatives. The ability of the isolates to produce lipase, esterase, cellulase, amylase, and gelatinase enzymes was tested using the agar diffusion method. The results showed a significant level of enzyme production (p < 0.05). Bacillus cereus (MZ571899) exhibited the highest esterase activity; Streptomyces thermocarboxydus (MZ571882) exhibited the highest lipase activity, Bacillus subtilis (MZ571887) exhibited the highest amylase activity, and Bacillus licheniformis (MZ571888) exhibited the highest cellulase activity, while Pseudomonas stutzeri (MZ571900) exhibited the highest gelatinase activity. We recommend further studies to characterize the isolates with low sequence percentage similarities to establish their true identities. In addition, further enzymatic studies are required to quantify, characterize, and purify these enzymes for industrial applications.

Extracellular lipase production from Bacillus cereus by using agro-industrial waste

Lipases are crucial biocatalysts in various industrial applications, and there is considerable interest in developing sustainable methods for their synthesis. This study focuses on the isolation, screening, and comparison of Bacillus cereus strains to produce extracellular lipases utilizing agro-industrial waste through solid-state fermentation. The results indicate that B. cereus exhibited optimal lipase production with soybean extract, yielding 41.2 ± 1.08 µ/ml (p < 0.05), followed by bagasse with 40.5 ± 0.97 µ/ml (p < 0.05). Other substrates, including rice bran (9.9 µ/ml), wheat bran (25.8 µ/ml), sunflower seed (24.0 µ/ml), and oat bran (10.2 µ/ml), demonstrated significantly lower enzyme activity. Additionally, lipase production from fruit peels was assessed, with banana yielding 21.1 µ/ml, orange 20.3 µ/ml, melon 16.3 µ/ml, and watermelon 16.43 µ/ml. Various oil wastes were also evaluated, showing lipase activities of 14.6 µ/ml (Sitara oil), 13.3 µ/ml (Shan oil), 11.0 µ/ml (automobile oil), and 10.2 µ/ml (cooking oil). The bacterial lipases produced from B. cereus demonstrated maximum hydrolysis of tributyrin agar medium at 40°C (p < 0.05). The findings suggest that utilizing different agro-industrial wastes for the production of extracellular lipase could help mitigate environmental pollution while providing a viable option for commercial enzyme production.

Agri-residues and agro-industrial waste substrates bioconversion by fungal cultures to biocatalyst lipase for green chemistry: A review

Huge amounts of agri-residues generated from food crops and processing are discarded in landfills, causing environmental problems. There is an urgent need to manage them with a green technological approach. Agri-residues are rich in nutrients such as proteins, lipids, sugars, minerals etc., and provide an opportunity for bioconversion into value-added products. Considering the importance of lipase as a biocatalyst for various industrial applications and its growing need for economic production, a detailed review of bioconversion of agri-residues and agro-industrial substrate for the production of lipase from fungal species from a technological perspective has been reported for the first time. Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) flow diagram was used for the identification and selection of articles from ScienceDirect, Google Scholar, and Scopus databases from 2010 to 2023 (July), and 108 peer-reviewed journal articles were included based on the scope of the study. The composition of agri-residues/agro-industrial wastes, fungal species, lipase production, industrial/green chemistry applications, and the economic impact of using agri-residues on lipase costs have been discussed. Bioconversion procedure, process developments, and technology gaps required to be addressed before commercialization have also been discussed. This process expects to decrease the environmental pollution from wastes, and low-cost lipase can help in the growth of the bioeconomy.

Current Insights in Fungal Importance-A Comprehensive Review

Besides plants and animals, the Fungi kingdom describes several species characterized by various forms and applications. They can be found in all habitats and play an essential role in the excellent functioning of the ecosystem, for example, as decomposers of plant material for the cycling of carbon and nutrients or as symbionts of plants. Furthermore, fungi have been used in many sectors for centuries, from producing food, beverages, and medications. Recently, they have gained significant recognition for protecting the environment, agriculture, and several industrial applications. The current article intends to review the beneficial roles of fungi used for a vast range of applications, such as the production of several enzymes and pigments, applications regarding food and pharmaceutical industries, the environment, and research domains, as well as the negative impacts of fungi (secondary metabolites production, etiological agents of diseases in plants, animals, and humans, as well as deteriogenic agents).

Bioprocessing and Screening of Indigenous Wastes for Hyper Production of Fungal Lipase

Background: Lipase is one of the most important enzymes produced from microbial fermentation. Agricultural wastes are a good source of enzyme production because they are cost-effective and production rates are also higher. Method: In this study, eight lignolitic substrates were screened for lipase production. Results: Out of these substrates, guava leaves showed maximum activity of 9.1 U/mL from Aspergillus niger by using the solid-state fermentation method. Various factors such as temperature, pH, incubation period, moisture content, inoculum size, and substrate size that influence the growth of fungi were optimized by response surface methodology (RSM), and then characterization was performed. When all physical and nutritional parameters were optimized by RSM, the maximum lipase activity obtained was 12.52 U/mL after 4 days of incubation, at pH 8, 40 °C temperature, 3 mL inoculum size, 20% moisture content, and 6 g substrate concentration. The enzyme was partially purified through 70% ammonium sulfate precipitation. After purification, it showed 34.291 U/mg enzyme activity, increasing the purification fold to 1.3. The enzyme was then further purified by dialysis, and the purification fold increased to 1.83 having enzyme activity of 48.03 U/mg. Furthermore, activity was increased to 132.72 U/mg after column chromatography. A purification fold of 5.07 was obtained after all purification steps.

Bati Butter as a Potential Substrate for Lipase Production by Aspergillus terreus NRRL-255

This study evaluated bati butter (Ouratea parviflora) as a substrate for lipase production by solid-state fermentation (SSF) using Aspergillus terreus NRRL-255. A gas chromatograph with a flame ionization detector determined the bati butter fatty acid profile. Lipase production and spore count were optimized using a 3² experimental design and evaluated using the response surface methodology. Moreover, the crude enzyme extract was evaluated against different pH, temperature, and activating and inhibitors reagents. Regarding the fatty acids identified, long-chain accounted for 78.60% of the total lipids. The highest lipase production was obtained at 35 °C and 120 h of fermentation, yielding 216.9 U g^-1. Crude enzyme extract presented more significant activity at 37 °C and pH 9. β-Mercaptoethanol increased the enzyme activity (113.80%), while sodium dodecyl sulfate inactivated the enzyme. Therefore, bati butter proved to be a potential substrate capable of inducing lipase production by solid-state fermentation.

Optimization and characterization of alkaliphilic lipase from a novel Bacillus cereus NC7401 strain isolated from diesel fuel polluted soil

Five Bacillus cereus strains including B. cereus AVP12, B. cereus NC7401, B. cereus BDBCO1, B. cereus JF70 and B. specie JL47 isolated from the diesel fuel polluted soil adhered to the roots of Tagetes minuta were screened for lipase production with phenol red agar method. B. cereus NC7401 strain successfully expressing and secreting lipase with maximal lipolytic activity was subjected to a submerged fermentation process with five different carbon (starch, glucose, maltose, fructose, and lactose) and five different nitrogen (tryptone, ammonium nitrate, peptone, urea, yeast extract) sources to produce lipase enzyme. Maximum enzyme activity was found with starch (30.6 UmL-1), maltose (40 UmL-1), and tryptone (38.6 UmL-1), and the lipases produced using these sources were named lipase A, B, and C respectively. The total protein content of 8.56, 8.86, and 2.75 μg mL-1 were obtained from B. cereus NC7401 cultured using starch, maltose, and tryptone respectively. Lipase was stable between temperature range 30–80°C and pH 5–10 whereas optimally active at 55°C and pH 8.0. The enzyme was relatively stable for 10 days at 4°C and its optimum reaction time with the substrate was 30 minutes. It was tolerant to 1.5% (v/v) methanol as an organic solvent, 1.5% (v/v) Triton X-100 as a media additive and 1.5% (w/v) Ni2+ as a metal ion. SDS, n-hexane, and Ag+ inhibited lipolytic activity. Oil stains were removed from cotton fabric which showed oil removal efficiency enhancement in the presence of a lipase. Fat hydrolysis of 20, 24, and 30% was achieved following 6 hours of incubation of the fat particles with lipase A, B, and C respectively at a concentration of 20 mg mL-1. To as best of our knowledge, this study on lipases extracted from bacteria of Azad Kashmir, Pakistan origin has never been reported before.

An encapsulated report on enzyme-assisted transesterification with an allusion to lipase

Biodiesel is a renewable, sulfur-free, toxic-free, and low carbon fuel which possesses enhanced lubricity. Transesterification is the easiest method employed for the production of biodiesel, in which the oil is transformed into biodiesel. Biocatalyst-mediated transesterification is more advantageous than chemical process because of its non-toxic nature, the requirement of mild reaction conditions, absence of saponification, easy product recovery, and production of high-quality biodiesel. Lipases are found to be the primary enzymes in enzyme-mediated transesterification process. Currently, researchers are using lipases as biocatalyst for transesterification. Lipases are extracted from various sources such as plants, microbes, and animals. Biocatalyst-based biodiesel production is not yet commercialized due to high-cost of purified enzymes and higher reaction time for the production process. However, research works are growing in the area of various cost-effective techniques for immobilizing lipase to improve its reusability. And further reduction in the production cost of lipases can be achieved by genetic engineering techniques. The reduction in reaction time can be achieved through ultrasonic-assisted biocatalytic transesterification. Biodiesel production by enzymatic transesterification is affected by many factors. Various methods have been developed to control these factors and improve biodiesel production. This report summarizes the various sources of lipase, various production strategies for lipase and the lipase-mediated transesterification. It is fully focused on the lipase enzyme and its role in biodiesel production. It also covers the detailed explanation of various influencing factors, which affect the lipase-mediated transesterification along with the limitations and scope of lipase in biodiesel production.

Application and characterization of crude fungal lipases used to degrade fat and oil wastes

Aspergillus niger MH078571.1 and A. niger MH079049.1 were identified previously as the two highest Aspergillus niger strains producing lipase. Biochemical characterizations of lipase activity and stability for these two strains were examined and revealed that the optimal temperature is 45 °C at pH 8for A. niger MH078571.1 and 55 °C for MH079049.1. The lipase production of both strains was studied on medium contains waste oil, as a cheap source to reduce the industrial cost, showed that the optimal incubation period for the enzyme production is 3 days. Moreover, an experiment on lipase activates in organic solvents demonstrated that 50% of acetone is the best solvent for the two strains. In the presence of surfactants, 0.1% of tween 80 surfactant showed the best lipase activities. Furthermore, Mg²⁺ and Zn²⁺ ions enhanced the lipase activity of A. niger MH078571.1, while Na²⁺ and Cu²⁺ enhanced the enzyme activity of A. niger MH079049.1. Lipase activity was also tested for industrial applications such as integrating it with different detergents. Maximum lipase activity was obtained with 1% of Omo as a powder detergent for both strains. In liquid detergent, 0.1% of Fairy showed maximum lipase activity in A. niger MH078571.1, while the lipase in A. niger MH079049.1 was more effective in 1% of Lux. Moreover, the degradation of natural animal fat with crude enzyme was tested using chicken and sheep fats. The results showed that more than 90% of fats degraded after 5 days of the incubation period.

Recent Advances in Feedstock and Lipase Research and Development towards Commercialization of Enzymatic Biodiesel

Biodiesel is a biodegradable, renewable, and carbon-neutral alternative to petroleum diesel that can contribute to the global effort of minimizing the use of fossil fuels and meeting the ever-growing energy demands and stringent environmental constraints. The aim of this work was to (1) review the recent progress in feedstock development, including first, second, third, and fourth-generation feedstocks for biodiesel production; (2) discuss recent progress in lipase research and development as one of the key factors for establishing a cost-competitive biodiesel process in terms of enzyme sources, properties, immobilization, and transesterification efficiency; and (3) provide an update of the current challenges and opportunities for biodiesel commercialization from techno-economic and social perspectives. Related biodiesel producers, markets, challenges, and opportunities for biodiesel commercialization, including environmental considerations, are critically discussed.

Thermostable lipases and their dynamics of improved enzymatic properties

Thermal stability is one of the most desirable characteristics in the search for novel lipases. The search for thermophilic microorganisms for synthesising functional enzyme biocatalysts with the ability to withstand high temperature, and capacity to maintain their native state in extreme conditions opens up new opportunities for their biotechnological applications. Thermophilic organisms are one of the most favoured organisms, whose distinctive characteristics are extremely related to their cellular constituent particularly biologically active proteins. Modifications on the enzyme structure are critical in optimizing the stability of enzyme to thermophilic conditions. Thermostable lipases are one of the most favourable enzymes used in food industries, pharmaceutical field, and actively been studied as potential biocatalyst in biodiesel production and other biotechnology application. Particularly, there is a trade-off between the use of enzymes in high concentration of organic solvents and product generation. Enhancement of the enzyme stability needs to be achieved for them to maintain their enzymatic activity regardless the environment. Various approaches on protein modification applied since decades ago conveyed a better understanding on how to improve the enzymatic properties in thermophilic bacteria. In fact, preliminary approach using advanced computational analysis is practically conducted before any modification is being performed experimentally. Apart from that, isolation of novel extremozymes from various microorganisms are offering great frontier in explaining the crucial native interaction within the molecules which could help in protein engineering. In this review, the thermostability prospect of lipases and the utility of protein engineering insights into achieving functional industrial usefulness at their high temperature habitat are highlighted. Similarly, the underlying thermodynamic and structural basis that defines the forces that stabilize these thermostable lipase is discussed. KEY POINTS: • The dynamics of lipases contributes to their non-covalent interactions and structural stability. • Thermostability can be enhanced by well-established genetic tools for improved kinetic efficiency. • Molecular dynamics greatly provides structure-function insights on thermodynamics of lipase.

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.

The Catalytic Activity of Biosynthesized Magnesium Oxide Nanoparticles (MgO-NPs) for Inhibiting the Growth of Pathogenic Microbes, Tanning Effluent Treatment, and Chromium Ion Removal

Magnesium oxide nanoparticles (MgO-NPs) were synthesized using the fungal strain Aspergillus terreus S1 to overcome the disadvantages of chemical and physical methods. The factors affecting the biosynthesis process were optimized as follows: concentration of Mg(NO3)2·6H2O precursor (3 mM), contact time (36 min), pH (8), and incubation temperature (35 °C). The characterization of biosynthesized MgO-NPs was accomplished using UV-vis spectroscopy, Fourier transform infrared (FT-IR) spectroscopy, transmission electron microscopy (TEM), scanning electron microscopy—energy dispersive X-ray (SEM-EDX), X-ray diffraction (XRD), and dynamic light scattering (DLS). Data confirmed the successful formation of crystallographic, spherical, well-dispersed MgO-NPs with a size range of 8.0–38.0 nm at a maximum surface plasmon resonance of 280 nm. The biological activities of biosynthesized MgO-NPs including antimicrobial activity, biotreatment of tanning effluent, and chromium ion removal were investigated. The highest growth inhibition of pathogenic Staphylococcus aureus, Bacillus subtilis, Pseudomonas aeruginosa, Escherichia coli, and Candida albicans was achieved at 200 μg mL–1 of MgO-NPs. The biosynthesized MgO-NPs exhibited high efficacy to decolorize the tanning effluent (96.8 ± 1.7% after 150 min at 1.0 µg mL–1) and greatly decrease chemical parameters including total suspended solids (TSS), total dissolved solids (TDS), biological oxygen demand (BOD), chemical oxygen demand (COD), and conductivity with percentages of 98.04, 98.3, 89.1, 97.2, and 97.7%, respectively. Further, the biosynthesized MgO-NPs showed a strong potential to remove chromium ions from the tanning effluent, from 835.3 mg L–1 to 21.0 mg L–1, with a removal percentage of 97.5%.

Cost-effective production of biocatalysts using inexpensive plant biomass: a review

Enzymes are the complex protein moieties, catalyze the rate of chemical reactions by transforming various substrates to specific products and play an integral part in multiple biochemical cycles. Advancement in enzyme research and its integration with industries have reformed the biotech industries. It provides a superior monetary and ecological exchange to traditional material measures in an efficient and environmentally sustainable manner. The cost-effective production of pure and highly active enzymes is still a challenge for the biocatalyst industries. The use of high purity substrates further raises the cost of a typical biocatalyst. The use of low-cost plant-based biomasses as an enticing and sustainable substrate for enzyme production is the most cost-effective approach to these problems. Given the relevance of biomass as a substrate for enzyme development, this review article focuses on the key source, composition and major enzyme generated using various biomass residues. Furthermore, the difficulties associated with the use of biomass as a substrate and technical developments in this area, are also addressed. The use of waste biomass as a substrate lowers the ultimate cost for the production of biocatalysts while simultaneously reduces the waste burden from the environment.

Complete genome sequence of lovastatin producer Aspergillus terreus ATCC 20542 and evaluation of genomic diversity among A. terreus strains

In the present study, the complete genome of a filamentous fungus Aspergillus terreus ATCC 20542 was sequenced, assembled, and annotated. This strain is mainly recognized for being a model wild-type lovastatin producer and a parental strain of high-yielding industrial mutants. It is also a microorganism with a rich repertoire of secondary metabolites that has been a subject of numerous bioprocess-related studies. In terms of continuity, the genomic sequence provided in this work is of the highest quality among all the publicly available genomes of A. terreus strains. The comparative analysis revealed considerable diversity with regard to the catalog of biosynthetic gene clusters found in A. terreus. Even though the cluster of lovastatin biosynthesis was found to be well-conserved at the species level, several unique genes putatively associated with metabolic functions were detected in A. terreus ATCC 20542 that were not detected in other investigated genomes. The analysis was conducted also in the context of the primary metabolic pathways (sugar catabolism, biomass degradation potential, organic acid production), where the visible differences in gene copy numbers were detected. However, the species-level genomic diversity of A. terreus was more evident for secondary metabolism than for the well-conserved primary metabolic pathways. The newly sequenced genome of A. terreus ATCC 20542 was found to harbor several unique sequences, which can be regarded as interesting subjects for future experimental efforts on A. terreus metabolism and fungal biosynthetic capabilities. KEY POINTS: • The high-quality genome of Aspergillus terreus ATCC 20542 has been assembled and annotated. • Comparative analysis with other sequenced Aspergillus terreus strains has revealed considerable diversity in biosynthetic gene repertoire, especially related to secondary metabolism. • The unique genomic features of A. terreus ATCC 20542 are discussed.

Microbial lipase: a new approach for a heterogeneous biocatalyst

Lipases are enzymes employed in several industrial process and their applicability can be increased if these biocatalysts are in the immobilize form. The objective of this work was to study the immobilization of lipase produced by submerged cultivation of Aspergillus sp. by hydrophobic interaction, evaluating its stability and reuse capacity. The immobilization process on octyl-sepharose (C₈) and octadecyl-sepabeads (C₁₈) carriers was possible after the removal of oil excess presented in the fermented broth. The results showed that the enzyme was isolated and concentrated in octyl-sepharose with 22% of the initial activity. To increase the amount of enzyme adsorbed on the carrier, 4 immobilization cycles were performed in a row, on the same carrier, with a final immobilization yield of 151.32% and an increase in the specific activity of 136%. The activity test with immobilized lipase showed that the immobilized enzyme maintained 75% of the initial activity after 20 cycles.

Turning cacay butter and wheat bran into substrate for lipase production by Aspergillus terreus NRRL-255

Cacay oil and butter were evaluated as enzymatic inducers for lipase production from Aspergillus terreus NRRL-255 by solid-state fermentation (SSF). Initially, physicochemical characteristics of agro-industrial wastes were evaluated in order to identify a potential solid substrate for lipase production. Higher water absorption index (3.65 g H₂O/g substrate), adequate mineral content, great carbon source, and nitrogen concentration were factors that influenced the choice of wheat bran as a solid substrate. Cacay butter presented the highest lipolytic activity (308.14 U g^-1) in the screening of lipid inducer. Then, the effects of lipid inducer concentration (cacay butter), temperature, pH, moisture, and fermentation time were evaluated on process performance using multivariate statistical methodology. Under optimal conditions, the highest lipase activity observed was 2,867.18 U g^-1. Regarding the lipase characterization, maximum relative activity was obtained at pH 7.0 and at 35 °C. An inhibitory effect was observed for Ca²⁺, Mn²⁺, Zn²⁺, Fe²⁺, and Cu²⁺ ions. Lipase activity was increased with the reduction of sodium dodecyl sulfate (SDS) concentration and the increase of Triton X-100. Therefore, the use of wheat bran as a solid substrate combined with cacay butter demonstrated a substantial lipase production, indicating its biotechnological industrial potential.

Reduction of scum accumulation through the addition of low-cost enzymatic extract in the feeding of high-rate anaerobic reactor

This work evaluates the reduction of scum accumulation on the top surface of upflow anaerobic sludge blanket (UASB) reactors by the addition of hydrolytic enzymes in their feed. For over 1 year, two UASB reactors of 1.4 L were maintained at 30 °C and continuously fed with synthetic domestic wastewater (containing 150 mg/L of soybean oil) under a hydraulic retention time of 10 h. The Control reactor was only fed with synthetic wastewater. Beginning at the 226th day of operation, low-cost hydrolytic enzymes (obtained by solid-state fermentation of Aspergillus terreus, a fungus isolated from a primary sewage sludge) were added into the feed of the other reactor (Test) for a lipase activity of 24 U/L, considerably reducing the formation of scum. In the Test reactor, the scum showed oil and grease (O&G) concentration between 0.8 and 1.3 g/L and an accumulation rate of 20 to 27 mg O&G/d. In the Control reactor, the scum had values twice as high (1.5-2.5 g/L and 34-51 mg O&G/d, respectively) and there were more operational problems. During the entire period of operation, both reactors presented high chemical oxygen demand removal (>80%), with no loss of effluent quality due to the addition of the enzymes.

Effects of cholinium-based ionic liquids on Aspergillus niger lipase: Stabilizers or inhibitors

Lipases are well-known biocatalysts used in several industrial processes/applications. Thus, as with other enzymes, changes in their surrounding environment and/or their thermodynamic parameters can induce structural changes that can increase, decrease, or even inhibit their catalytic activity. The use of ionic compounds as solvents or additives is a common approach for adjusting reaction conditions and, consequently, for controlling the biocatalytic activity of enzymes. Herein, to elucidate the effects of ionic compounds on the structure of lipase, the stability and enzymatic activity of lipase from Aspergillus niger in aqueous solutions (at 0.05, 0.10, 0.50, and 1.00 M) of six cholinium-based ionic liquids (cholinium chloride [Ch]Cl; cholinium acetate ([Ch][Ac]); cholinium propanoate ([Ch][Prop]); cholinium butanoate ([Ch][But]); cholinium pentanoate ([Ch][Pent]); and cholinium hexanoate ([Ch][Hex])) were evaluated over 24 hr. The enzymatic activity of lipase was maintained or enhanced in the lower concentrations of all the [Ch]⁺ -ILs (below 0.1 M). [Ch][Ac] maintained the biocatalytic behavior of lipase, independent of the IL concentration and incubation time. However, above 0.1 M, [Ch][Pent] and [Ch][Hex] caused complete inhibition of the catalytic activity of the enzyme, demonstrating that the increase in the anionic alkyl chain length strongly affected the conformation of the lipase. The hydrophobicity and concentration of the [Ch]⁺ -ILs play an important role in the enzyme activity, and these parameters can be controlled by adjusting the anionic alkyl chain length. The inhibitory effects of [Ch][Pent] and [Ch][Hex] may be of great interest to the pharmaceutical industry to induce pharmacological inhibition of gastric and pancreatic lipases.

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.

An alkaline and surfactant-tolerant lipase from Trichoderma lentiforme ACCC30425 with high application potential in the detergent industry

Alkaline lipases with adaptability to low temperatures and strong surfactant tolerance are favorable for application in the detergent industry. In the present study, a lipase-encoding gene, TllipA, was cloned from Trichoderma lentiforme ACCC30425 and expressed in Pichia pastoris GS115. The purified recombinant TlLipA was found to have optimal activities at 50 °C and pH 9.5 and retain stable over the pH range of 6.0–10.0 and 40 °C and below. When using esters of different lengths as substrates, TlLipA showed preference for the medium length p-nitrophenyl octanoate. In comparison to commercial lipases, TlLipA demonstrated higher tolerance to various surfactants (SDS, Tween 20, and Triton X100) and retained more activities after incubation with Triton X100 for up to 24 h. These favorable characteristics make TlLipA prospective as an additive in the detergent industry.

Realm of Thermoalkaline Lipases in Bioprocess Commodities

For decades, microbial lipases are notably used as biocatalysts and efficiently catalyze various processes in many important industries. Biocatalysts are less corrosive to industrial equipment and due to their substrate specificity and regioselectivity they produced less harmful waste which promotes environmental sustainability. At present, thermostable and alkaline tolerant lipases have gained enormous interest as biocatalyst due to their stability and robustness under high temperature and alkaline environment operation. Several characteristics of the thermostable and alkaline tolerant lipases are discussed. Their molecular weight and resistance towards a range of temperature, pH, metal, and surfactants are compared. Their industrial applications in biodiesel, biodetergents, biodegreasing, and other types of bioconversions are also described. This review also discusses the advance of fermentation process for thermostable and alkaline tolerant lipases production focusing on the process development in microorganism selection and strain improvement, culture medium optimization via several optimization techniques (i.e., one-factor-at-a-time, surface response methodology, and artificial neural network), and other fermentation parameters (i.e., inoculums size, temperature, pH, agitation rate, dissolved oxygen tension (DOT), and aeration rate). Two common fermentation techniques for thermostable and alkaline tolerant lipases production which are solid-state and submerged fermentation methods are compared and discussed. Recent optimization approaches using evolutionary algorithms (i.e., Genetic Algorithm, Differential Evolution, and Particle Swarm Optimization) are also highlighted in this article.

Extracellular Alkaline Lipase from a Novel Fungus Curvularia sp. DHE 5: Optimisation of Physicochemical Parameters, Partial Purification and Characterisation

Thirty isolated fungal strains were screened for lipase production using Phenol Red plates, containing tributyrin as lipidic substrate, and a novel fungus identified genetically as Curvularia sp. DHE 5 was found as the most prominent strain. Various agro-industrial substrates were evaluated as inert supports for lipase production in solid-state fermentation. The highest yield of lipase ((83.4±2.2) U/g on dry mass basis) was reported with wheat bran medium after seven days of fermentation at pH=7.0, temperature of 30 °C, 70% moisture content, inoculum size of 1.27·10⁷ spore/mL and 2% olive oil as an inducer. Supplementation of the medium with 0.05% KCl as an ion source further increased lipase production to (88.9±1.2) U/g on dry mass basis. The enzyme was partially purified through ammonium sulphate fractionation (40%) followed by dialysis, and its optimum pH and temperature were reported at 8.0 and 50 °C, respectively, with remarkable pH and thermal stability.

Enhancement of lipase activity for the oily wastewater treatment by an electrostimulation process

The efficacy of electrostimulation on bacterial lipase activity and COD removal was studied using a laboratory bioelectrochemical system.