Coconut cake - a potent substrate for the production of lipase byCandida rugosa in solid-state fermentation

Valorization of Food Waste to Produce Value-Added Products Based on Its Bioactive Compounds

The rapid growth of the global population and changes in lifestyle have led to a significant increase in food waste from various industrial, agricultural, and household sources. Nearly one-third of the food produced annually is wasted, resulting in severe resource depletion. Food waste contains rich organic matter, which, if not managed properly, can pose a serious threat to the environment and human health, making the proper disposal of food waste an urgent global issue. However, various types of food waste, such as waste from fruit, vegetables, grains, and other food production and processing, contain important bioactive compounds, such as polyphenols, dietary fiber, proteins, lipids, vitamins, organic acids, and minerals, some of which are found in greater quantities in the discarded parts than in the parts accepted by the market. These bioactive compounds offer the potential to convert food waste into value-added products, and fields including nutritional foods, bioplastics, bioenergy, biosurfactants, biofertilizers, and single cell proteins have welcomed food waste as a novel source. This review reveals the latest insights into the various sources of food waste and the potential of utilizing bioactive compounds to convert it into value-added products, thus enhancing people’s confidence in better utilizing and managing food waste.

Microbial strategies for bio-transforming food waste into resources

With the changing life-style and rapid urbanization of global population, there is increased generation of food waste from various industrial, agricultural, and household sources. According to Food and Agriculture Organization (FAO), almost one-third of the total food produced annually is wasted. This poses serious concern as not only there is loss of rich resources; their disposal in environment causes concern too. Food waste is rich in organic, thus traditional approaches of land-filling and incineration could cause severe environmental and human health hazard by generating toxic gases. Thus, employing biological methods for the treatment of such waste offers a sustainable way for valorization. This review comprehensively discusses state-of-art knowledge about various sources of food waste generation, their utilization, and valorization by exploiting microorganisms. The use of microorganisms either aerobically or anaerobically could be a sustainable and eco-friendly solution for food waste management by generating biofuels, electrical energy, biosurfactants, bioplastics, biofertilizers, etc.

Utilization of coconut oil cake for the production of lipase using Bacillus coagulans VKL1

The overproduction of enzymes was performed by manipulating the medium components. In our study, solvent-tolerant thermophilic lipase-producing Bacillus coagulans was isolated from soil samples and a stepwise optimization strategy was employed to increase the lipase production using coconut oil cake basal medium. In the first step, the influence of pH, temperature, carbon source, nitrogen source and inducers on lipase activity was investigated by the One-Factor-At-A-Time (OFAT) method. In the second step, the three significant factors resulted from OFAT were optimized by the statistical approach (CCD).The optimum values of olive oil (0.5%), Tween 80 (0.6%) and FeSO4 (0.05%) was found to be responsible for a 3.2-fold increase in the lipase production identified by Central Composite Design.

Quantitative approach to track lipase producing Pseudomonas sp. S1 in nonsterilized solid state fermentation

Proliferation of the inoculated Pseudomonas sp. S1 is quantitatively evaluated using ERIC-PCR during the production of lipase in nonsterile solid state fermentation an approach to reduce the cost of enzyme production. Under nonsterile solid state fermentation with olive oil cake, Pseudomonas sp. S1 produced 57·9 IU g(-1) of lipase. DNA fingerprints of unknown bacterial isolates obtained on Bushnell Haas agar (BHA) + tributyrin exactly matched with that of Pseudomonas sp. S1. Using PCR-based enumeration, population of Pseudomonas sp. S1 was proliferated from 7·6 × 10(4) CFU g(-1) after 24 h to 4·6 × 10(8) CFU g(-1) after 96 h, which tallied with the maximum lipase activity as compared to control. Under submerged fermentation (SmF), Pseudomonas sp. S1 produced maximum lipase (49 IU ml(-1) ) using olive oil as substrate, while lipase production was 9·754 IU ml(-1) when Pseudomonas sp. S1 was grown on tributyrin. Optimum pH and temperature of the crude lipase was 7·0 and 50°C. Crude enzyme activity was 71·2% stable at 50°C for 360 min. Pseudomonas sp. S1 lipase was also stable in methanol showing 91·6% activity in the presence of 15% methanol, whereas 75·5 and 51·1% of activity were retained in the presence of 20 and 30% methanol, respectively. Thus, lipase produced by Pseudomonas sp. S1 is suitable for the production of biodiesel as well as treatment of oily waste water.

SIGNIFICANCE AND IMPACT OF STUDY

This study presents the first report on the production of thermophilic organic solvent tolerant lipase using agro-industry waste in nonsterile solid state fermentation. Positive correlation between survival of Pseudomonas sp. S1 and lipase production under nonsterile solid state fermentation was established, which may emphasize the need to combine molecular tools and solid state fermentation in future studies. Our study brings new insights into the lipase production in cost-effective manner, which is an industrially relevant approach.

Optimization of L-asparaginase production by Serratia marcescens (NCIM 2919) under solid state fermentation using coconut oil cake

Background

The present study focused on utilization of agrowaste byproducts generated from oil mill for L-asparaginase enzyme production using Serratia marcescens under solid state fermentation. Classical and statistical methods were employed to optimize the process variables and the results were compared.

Results

The classical one factor at a time (OFAT) and response surface methodology (RSM) are employed to optimize the fermentation process. When used as the sole carbon source in SSF, coconut oil cake (COC) showed maximum enzyme production. The optimal values of substrate amount, initial moisture content, pH and temperature were found to be 6 g, 40%, 6 and 35°C respectively under classical optimization method with maximum enzyme activity of 3.87 (U gds-1). Maximum enzyme activity of 5.86 U gds-1 was obtained at the predicted optimal conditions of substrate amount 7.6 g of COC, initial moisture content of substrate 50%, temperature 35.5°C and pH 7.4. Validation results proved that a good relation existed between the experimental and the predicted model.

Conclusions

RSM optimization approach enhances the enzyme production to 33% when compared to classical method. Utilization of coconut oil cake as a low cost substrate in SSF for L-asparaginase production makes the process economical and also reduces the environmental pollution by converting the oil mill solid waste into a useful bioproduct.

Adding value to the oil cake as a waste from oil processing industry: production of lipase and protease by Candida utilis in solid state fermentation

Olive oil cake is a by-product from the olive oil processing industry and can be used for the lipase and protease production by Candida utilis in solid state fermentation. Different carbon and nitrogen sources were evaluated, and the results showed that the supplementation of the substrate with maltose and starch as carbon sources and yeast extract as a nitrogen source significantly increased the lipase production. The best results were obtained with maltose, whereas rather low lipase and protease activities were found with glucose and oleic acid. Response surface methodology and a five-level-three-factor central composite rotatable design were used to evaluate the effects of the initial moisture content, inoculum size and fermentation time on both lipase and protease activity levels. A lipase activity value of ≈25 U g(-1) and a protease activity value of 110 U g(-1) were obtained under the optimized fermentation conditions. An alkaline treatment of the substrate appeared to be efficient, leading to increases of 39% and 133% in the lipase and protease production, respectively. The results showed that the olive cake could be a good source for enzyme production by solid state fermentation.

Production of a solvent, detergent, and thermotolerant lipase by a newly isolated Acinetobacter sp. in submerged and solid-state fermentations

The lipase production ability of a newly isolated Acinetobacter sp. in submerged (SmF) and solid-state (SSF) fermentations was evaluated. The results demonstrated this strain as one of the rare bacterium, which is able to grow and produce lipase in SSF even more than SmF. Coconut oil cake as a cheap agroindustrial residue was employed as the solid substrate. The lipase production was optimized in both media using artificial neural network. Multilayer normal and full feed forward backpropagation networks were selected to build predictive models to optimize the culture parameters for lipase production in SmF and SSF systems, respectively. The produced models for both systems showed high predictive accuracy where the obtained conditions were close together. The produced enzyme was characterized as a thermotolerant lipase, although the organism was mesophile. The optimum temperature for the enzyme activity was 45°C where 63% of its activity remained at 70°C after 2 h. This lipase remained active after 24 h in a broad range of pH (6-11). The lipase demonstrated strong solvent and detergent tolerance potentials. Therefore, this inexpensive lipase production for such a potent and industrially valuable lipase is promising and of considerable commercial interest for biotechnological applications.

Production of Cold-Active Bacterial Lipases through Semisolid State Fermentation Using Oil Cakes

Production of cold active lipase by semisolid state fermentation involves the use of agroindustrial residues. In the present study, semisolid state fermentation was carried out for the production of cold active lipase using Micrococcus roseus, isolated from soil samples of Gangotri glaciers, Western Himalayas. Among various substrate tested, groundnut oil cake (GOC) favored maximal yield of lipases at 15 ± 1°C within 48 h. Supplementation of glucose 1% (w/v) as additional carbon source and ammonium nitrate 2% (w/v) as additional nitrogen source enhanced production of lipase. Addition of triglycerides 0.5% (v/v) tends to repress the lipase production. Further mixed preparation of groundnut oil cake (GOC) along with mustard oil cake (MOC) in the ratio of 1 : 1, and its optimization resulted in improved production of cold active lipase. The enzyme exhibited maximum activity at 10–15°C and was stable at temperatures lower than 30°C. The lipase exhibited optimum activity at pH 8 and showed more than 60% stability at pH 9. Semisolid state fermentation process by utilizing agroindustrial wastes will direct to large-scale commercialization of lipase catalyzed process in cost-effective systems.

Scale up of a novel tri-substrate fermentation for enhanced production of Aspergillus niger lipase for tallow hydrolysis

A novel tri-substrate fermentation (TSF) process was developed for the production of lipase from Aspergillus niger MTCC 2594 using agro-industrial residues, wheat bran (WB), coconut oil cake (COC) and an agro-product, wheat rawa (WR). The lipase activity was 628.7+/-13 U/g dry substrate (U/gds) at 30 degrees C and 96 h and growth studies indicated that addition of WR significantly augmented the biomass and lipase production. Scale up of lipase production at 100g and 3 kg (3 x 1 kg) tray-level batch fermentation resulted in 96% and 83.0% of enzyme activities, respectively, at 72 h. Maximum activity of 745.7+/-11U/gds was obtained, when fermented substrate was extracted in buffer containing 1% (w/v) sodium chloride and 0.5% (w/v) Triton X-100. Furthermore, the direct application of fermented substrate for tallow hydrolysis makes the process economical for industrial production of biofuel.

Optimization of extracellular psychrophilic alkaline lipase produced by marine Pseudomonas sp. (MSI057)

An endosymbiotic Pseudomonas sp. (MSI057), which could produce high yields of lipase, was isolated from marine sponge Dendrilla nigra, collected from the peninsular coast of India. Maximum production of enzyme was obtained in minimal medium supplemented with 1% tributyrin. Catabolite repression was observed when the medium was supplemented with readily available carbon sources. The optimum temperature and pH for the enzyme production was 30 degrees C and 9.0, respectively. The enzyme exhibited maximum activity in pH range of 8-9 with an optimum pH 9.0. The activity of purified enzyme was optimum at 37 degrees C and showed 80% activity at 20 degrees C and the enzyme activity decreased dramatically above 50 degrees C. Based on the present findings, the enzyme was characterized as psychrophilic alkaline lipase, which can be developed for industrial applications.

Oil cakes and their biotechnological applications--a review

Oil cakes have been in use for feed applications to poultry, fish and swine industry. Being rich in protein, some of these have also been considered ideal for food supplementation. However, with increasing emphasis on cost reduction of industrial processes and value addition to agro-industrial residues, oil cakes could be ideal source of proteinaceous nutrients and as support matrix for various biotechnological processes. Several oil cakes, in particular edible oil cakes offer potential benefits when utilized as substrate for bioprocesses. These have been utilized for fermentative production of enzymes, antibiotics, mushrooms, etc. Biotechnological applications of oil cakes also include their usages for vitamins and antioxidants production. This review discusses various applications of oil cakes in fermentation and biotechnological processes, their value addition by implementation in feed and energy source (for the production of biogas, bio-oil) as well.

Mixed substrate solid state fermentation for production and extraction of lipase from Aspergillus niger MTCC 2594

A novel mixed substrate solid-state fermentation (SSF) process has been developed for Aspergillus niger MTCC 2594 using wheat bran (WB) and gingelly oil cake (GOC) and the results showed that addition of GOC to WB (WB : GOC, 3 : 1, w/w) increased the lipase activity by 36.0% and the activity was 384.3+/-4.5 U/g dry substrate at 30 degrees C and 72 h. Scale up of lipase production to 100 g and 1 kg tray-level batch fermentation resulted in 95.0% and 84.0% of enzyme activities respectively at 72 h. A three-stage multiple contact counter-current extraction yielded 97% enzyme recovery with a contact time of 60 min. However, extraction by simple percolation and plug-flow methods resulted in decreased enzyme recoveries. The mixed substrate SSF process has resulted in a significant increase in specific activity (58.9%) when compared to a submerged fermentation (SmF) system. Furthermore, an efficient process of extraction has been standardized with this process. Use of GOC along with WB as potential raw materials for enzyme production could be of great commercial significance. This is the first report on the production and extraction of lipase from Aspergillus niger using mixed solid substrates, WB and GOC, which are potential raw materials for the production of enzymes and other value-added products.

A review on hydrolytic enzymes in the treatment of wastewater with high oil and grease content

Wastewater from dairies and slaughterhouses contains high levels of fats and proteins that present low biodegradability. A large number of pretreatment systems are employed to remove oil and grease (O&G) to prevent a host of problems that may otherwise arise in the biological process, and reduce the efficiency of the treatment station. Problems caused by excessive O&G include a reduction in the cell-aqueous phase transfer rates, a sedimentation hindrance due to the development of filamentous microorganisms, development and flotation of sludge with poor activity, clogging and the emergence of unpleasant odors. Therefore the application of a pretreatment to hydrolyze and dissolve lipids may improve the biological degradation of fatty wastewaters, accelerating the process and improving time efficiency. However thus far, only a few studies describing the degradation of fats and oils by alkaline/acid/enzymatic hydrolysis have been reported; the treatment of effluents from several origins is a new and promising application for lipases. Among the strains that produce the hydrolytic enzymes studied, the fungus Penicillium restrictum is a particularly promising one. When cultivated in low-cost solid medium composed of agro-industrial waste, P. restrictum produces a pool of hydrolases capable of degrading the most complex organic compounds. This degradation enables a considerable increase in organic matter removal efficiency to be realized, which results in the attainment of a high-quality effluent in the subsequent biological treatment stage. Consequently, there is presently a wide variety of ongoing scientific investigation in the field of developing enzymatic hydrolysis processes to precede traditional biological treatment.

Biochemical engineering aspects of solid state bioprocessing

Despite centuries of use and renewed interest over the last 20 years in solid-state fermentation (SSF) technology, and despite its good potential for a range of products, there are currently relatively few large-scale commercial applications. This situation can be attributed to the complexity of the system: Macroscale and microscale heat and mass transfer limitations are intrinsic to the system, and it is only over the last decade or so that we have begun to understand them. This review presents the current state of understanding of biochemical engineering aspects of SSF processing, including not only the fermentation itself, but also the auxiliary steps of substrate and inoculum preparation and downstream processing and waste disposal. The fermentation step has received most research attention. Significant advances have been made over the last decade in understanding how the performance of SSF bioreactors can be controlled either by the intraparticle processes of enzyme and oxygen diffusion or by the macroscale heat transfer processes of conduction, convection, and evaporation. Mathematical modeling has played an important role in suggesting how SSF bioreactors should be designed and operated. However, these models have been developed on the basis of laboratory-scale data and there is an urgent need to test these models with data obtained in large-scale bioreactors.

Candida rugosa lipases: molecular biology and versatility in biotechnology

This review describes how the versatile Candida rugosa lipases (CRL) have extended the frontiers of biotechnology. As evidenced by the current literature, CRL claims more applications than any other biocatalyst. This review comprises a detailed discussion on the molecular biology of CRL, its versatile catalytic reactions, broad specificities and diverse immobilization strategies. It also discusses its role in the food and flavour industry, the production of ice cream and single cell protein, biocatalytic resolution of life-saving pharmaceuticals, carbohydrate esters and amino acid derivatives unobtainable by conventional chemical synthesis, potent biocide making, biosensor modulations, eco-friendly approach and bioremediation, biosurfactants in detergent making, and recently, cosmetics and perfumery.