Amylase Production by Saccharomycopsis fibuligera A11 in Solid-State Fermentation for Hydrolysis of Cassava Starch

The optimization of process parameters for high amylase production by Saccharomycopsis fibuligera A11 in solid-state fermentation was carried out using central composite design. Finally, the optimal parameters obtained with the response surface methodology (RSM) were moisture 610.0 ml/kg, inoculum 30.0 ml (OD_600 nm = 20.0)/kg, the amount ratio of wheat bran to rice husk 0.42, cassava starch concentration 20.0 g/kg, temperature 28 °C, and natural pH. Under the optimized conditions, 4,296 U/g of dry substrate of amylase activity was reached in the solid-state fermentation culture of the yeast strain A11 within 160 h, whereas the predicted maximum amylase activity of 4,222 U/g of dry substrate of amylase activity was derived from the RSM regression. It was found that cassava starch can be actively converted into monosaccharides and oligosaccharides by the crude amylase.     

Xylanase Production by <Emphasis Type="Italic">Penicillium canescens</Emphasis> on Soya Oil Cake in Solid-State Fermentation

There is an increasing interest for the organic residues from various sectors of agriculture and industries over the past few decades. Their application in the field of fermentation technology has resulted in the production of bulk chemicals and value-added products such as amino acid, enzymes, mushroom, organic acids, single-cell protein, biologically active secondary metabolites, etc. (Ramachandran et al., Bioresource Technology 98:2000–2009, 2007). In this work, the production of extracellular xylanase by the fungus Penicillium canescens was investigated in solid-state fermentation using five agro-industrial substrates (soya oil cake, soya meal, wheat bran, whole wheat bran, and pulp beet). The best substrate was the soya oil cake. In order to optimize the production, the most effective cultivation conditions were investigated in Erlenmeyer flasks and in plastic bags with 5 and 100 g of soya oil cake, respectively. The initial moisture content, initial pH, and temperature of the culture affected the xylanase synthesis. The optimal fermentation medium was composed by soya oil cake crushed to 5 mm supplemented with 3% and 4% (w/w) of casein peptone and Na₂HPO₄.2H₂O. After 7 days of incubation at 30 °C and under 80% of initial moisture, a xylanase production level of 18,895 ± 778 U/g (Erlenmeyer flasks) and 9,300 ± 589 U/g (plastic bags) was reached. The partially purified enzyme recovered by ammonium sulfate fractionation was completely stable at freezing and refrigeration temperatures up to 6 months and reasonably stable at room temperature for more than 3 months.     

Compactin Production Studies Using <Emphasis Type="Italic">Penicillium brevicompactum</Emphasis> Under Solid-State Fermentation Conditions

In the present study, compactin production by Penicillium brevicompactum WA 2315 was optimized using solid-state fermentation. The initial one factor at a time approach resulted in improved compactin production of 905 μg gds⁻¹ compared to initial 450 μg gds⁻¹. Subsequently, nutritional, physiological, and biological parameters were screened using fractional factorial and Box–Behnken design. The fractional factorial design studied inoculum age, inoculum volume, pH, NaCl, NH₄NO₃, MgSO₄, and KH₂PO₄. All parameters were found to be significant except pH and KH₂PO₄. The Box–Behnken design studied inoculum volume, inoculum age, glycerol, and NH₄NO₃ at three different levels. Inoculum volume (p = 0.0013) and glycerol (p = 0.0001) were significant factors with greater effect on response. The interaction effects were not significant. The validation study using model-defined conditions resulted in an improved yield of 1,250 μg gds⁻¹ compactin. Further improvement in yield was obtained using fed batch mode of carbon supplementation. The feeding of glycerol (20% v/v) on day 3 resulted in further improved compactin yield of 1,406 μg gds⁻¹. The present study demonstrates that agro-industrial residues can be successfully used for compactin production, and statistical experiment designs provide an easy tool to improve the process conditions for secondary metabolite production.     

Variable Volume Fed-Batch Fermentation for Nisin Production by <Emphasis Type="Italic">Lactococcus lactis</Emphasis> subsp<Emphasis Type="Italic">. lactis W28</Emphasis>

A feeding technology that was suitable for improving the nisin production by Lactococcus lactis subsp. lactis W28 was established. The effects of initial sucrose concentration (ISC) in the fermentation broth, feeding time, and feeding rate on the fermentation were studied. It was observed that a fed-batch culture (ISC = 10 g l⁻¹) with 100 ml sucrose solution (190 g l⁻¹) being evenly fed (9–10 ml h⁻¹) into the fermenter after 3-h fermentation gave the best performance in terms of biomass and nisin yield. Under these conditions, the total biomass and the total nisin yield were approximately 23% and 51% higher than those in batch fermentation, respectively. When the sucrose concentration was controlled at 5–10 g l⁻¹ in variable volume intermittent fed-batch fermentation (VVIF) with ISC = 10 g l⁻¹, the total biomass and the total nisin yield were 29% and 60% above those in batch fermentation, respectively. The VVIF proved to be effective to eliminate the substrate inhibition by maintaining sucrose at appropriate levels. It is also easy to be scaled up, since various parameters involved in industrial production were taken into account.     

Adding Value to the Oil Cake as a Waste from Oil Processing Industry: Production of Lipase and Protease by <Emphasis Type="Italic">Candida utilis</Emphasis> 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.     

Keratinase Production by Endophytic <Emphasis Type="Italic">Penicillium</Emphasis> spp. Morsy1 Under Solid-State Fermentation Using Rice Straw

Among all endophytic keratinolytic fungal isolates recovered from marine soft coral Dendronephthya hemprichii, Penicillium spp. Morsy1 was selected as the hyperactive keratinolytic strain under solid substrate fermentation of different agriculture and poultry wastes. The optimization of extraction process, physicochemical parameters affecting the keratinase production in solid-state fermentation, and the purified keratinase parameters were studied. Maximum keratinase activity (1,600 U g⁻¹, initial dry substrate) was recovered from moldy bran with 0.1% Tween 80. The optimized production conditions were rice straw as carbon source, pH of medium 6, growth temperature 26 °C, initial moisture content of 80% (v/w), inoculum size of 10⁵ spores ml⁻¹, and an average particle size of the substrate 0.6 mm (3,560 U g⁻¹, initial dry substrate after 5 days of fermentation). Two types of keratinase (Ahm1 and Ahm2) were purified from the culture supernatant through ammonium sulfate precipitation, DEAE-Sepharose, and gel filtration chromatography. Enzyme molecular weights were 19 kDa (Ahm1) and 40 kDa (Ahm2). The kinetic parameters of purified keratinases were optimized for the hydrolysis of azokeratin by Ahm1 (pH 7.0–8.0, stable in pH range of 6.0 to 8.0 at 50 °C) and Ahm2 enzymes (pH 10.0–11.0, stable in pH range of 6.0 to 11.0 at 60–65 °C). Whereas inhibitors of serine (phenylmethylsulfonyl fluoride) and cysteine (iodoacetamide) proteases had minor effects on both Ahm1 and Ahm2 activity, both keratinases were strongly inhibited by chelating agents EDTA and EGTA. These findings suggest that serine and cysteine residues are not involved in the catalytic mechanisms, and they are metalloproteases.     

Improvement on Citric Acid Production in Solid-state Fermentation by <Emphasis Type="Italic">Aspergillus niger</Emphasis> LPB BC Mutant Using Citric Pulp

Citric acid (CA) production has been conducted through a careful strain selection, physical–chemical optimization and mutation. The aim of this work was to optimize the physical–chemical conditions of CA production by solid-state fermentation (SSF) using the Aspergillus niger LPB BC strain, which was isolated in our laboratory. The parental and mutant strain showed a good production of CA using citric pulp (CP) as a substrate. The physical–chemical parameters were optimized and the best production was reached at 65% moisture, 30 °C and pH 5.5. The influence of the addition of commercial and alternative sugars, nitrogen sources, salts, and alcohols was also studied. The best results (445.4 g of CA/kg of CP) were obtained with sugarcane molasses and 4% methanol (v/w). The mutagenesis induction of LPB BC was performed with UV irradiation. Eleven mutant strains were tested in SSF where two mutants showed a higher CA production when compared to the parental strain. A. niger LPB B3 produced 537.6 g of CA/kg of CP on the sixth day of fermentation, while A. niger LPB B6 produced 616.5 g of CA/kg of CP on the fourth day of fermentation, representing a 19.5% and 37% gain, respectively.     

A Process to Produce Penicillin G Acylase by Surface-Adhesion Fermentation Using <Emphasis Type="Italic">Mucor griseocyanus</Emphasis> to Obtain 6-Aminopenicillanic Acid by Penicillin G Hydrolysis

The production of extracellular and mycelia-associated penicillin G acylase (maPGA) with Mucor griseocyanus H/55.1.1 by surface-adhesion fermentation using Opuntia imbricata, a cactus, as a natural immobilization support was studied. Enzyme activity to form 6-aminopencillanic acid (6-APA) from penicillin G was assayed spectrophotometrically. The penicillin G hydrolysis to 6-APA was evaluated at six different times using PGA samples recovered from the skim milk medium at five different incubation times. Additionally, the effect of varying the penicillin G substrate concentration level on the PGA enzyme activity was also studied. The maximum reaction rate, V _max, and the Michaelis constant, K _M, were determined using the Michaelis–Menten model. The maximum levels for maPGA and extracellular activity were found to be 2,126.50 international unit per liter (IU/l; equal to 997.83 IU/g of support) at 48 h and 755.33 IU/l at 60 h, respectively. Kinetics of biomass production for total biomass showed a maximum growth at 60 h of 3.36 and 2.55 g/l (equal to 0.012 g of biomass per gram of support) for the immobilized M. griseocyanus biomass. The maPGA was employed for the hydrolysis of penicillin G to obtain 6-APA in a batch reactor. The highest quantity of 6-APA obtained was 226.16 mg/l after 40-min reaction. The effect of substrate concentration on maPGA activity was evaluated at different concentrations of penicillin G (0–10 mM). K _M and V _max were determined to be 3.0 × 10⁻³ M and 4.4 × 10⁻³ mM/min, respectively.     

Examining the Potential of Plasma-Assisted Pretreated Wheat Straw for Enzyme Production by <Emphasis Type="Italic">Trichoderma reesei</Emphasis>

Plasma-assisted pretreated wheat straw was investigated for cellulase and xylanase production by Trichoderma reesei fermentation. Fermentations were conducted with media containing washed and unwashed plasma-assisted pretreated wheat straw as carbon source which was sterilized by autoclavation. To account for any effects of autoclavation, a comparison was made with unsterilized media containing antibiotics. It was found that unsterilized washed plasma-assisted pretreated wheat straw (which contained antibiotics) was best suited for the production of xylanases (110 IU ml⁻¹) and cellulases (0.5 filter paper units (FPU) ml⁻¹). Addition of Avicel boosted enzyme titers with the highest cellulase titers (1.5 FPU ml⁻¹) found with addition of 50 % w/w Avicel and with the highest xylanase production (350 IU ml⁻¹) reached in the presence of 10 % w/w Avicel. Comparison with enzyme titers from other nonrefined feedstocks suggests that plasma pretreated wheat straw is a promising and suitable substrate for cellulase and hemicellulase production.     

Solid-state Fermentation for Enhanced Production of Laccase using Indigenously Isolated <Emphasis Type="Italic">Ganoderma</Emphasis> sp.

Laccase production by solid-state fermentation (SSF) using an indigenously isolated white rot basidiomycete Ganoderma sp. was studied. Among the various agricultural wastes tested, wheat bran was found to be the best substrate for laccase production. Solid-state fermentation parameters such as optimum substrate, initial moisture content, and inoculum size were optimized using the one-factor-at-a-time method. A maximum laccase yield of 2,400 U/g dry substrate (U/gds) was obtained using wheat bran as substrate with 70% initial moisture content at 25°C and the seven agar plugs as the inoculum. Further enhancement in laccase production was achieved by supplementing the solid-state medium with additional carbon and nitrogen source such as starch and yeast extract. This medium was optimized by response surface methodology, and a fourfold increase in laccase activity (10,050 U/g dry substrate) was achieved. Thus, the indigenous isolate seems to be a potential laccase producer using SSF. The process also promises economic utilization and value addition of agro-residues.     

Ethanol Production from H<Subscript>2</Subscript>SO<Subscript>3</Subscript>-Steam-Pretreated Fresh Sweet Sorghum Stem by Simultaneous Saccharification and Fermentation

The present work presents an alternative approach to ethanol production from sweet sorghum: without detoxification, acid-impregnated fresh sweet sorghum stem which contains soluble (glucose and sucrose) and insoluble carbohydrates (cellulose and hemicellulose) was steam pretreated under mild temperature of 100 °C. Simultaneous saccharification and fermentation experiments were performed on the pretreated slurries using Saccharomyces cerevisiae. Experimentally, ground fresh sweet sorghum stem was combined with H₂SO₃ at dosages of 0.25, 0.50, and 0.75 g/g dry matter (DM) and steam pretreated by varying the residence time (60, 120, or 240 min). According to enzymatic hydrolysis results and ethanol yields, H₂SO₃ was a powerful and mild acid for improving enzymatic digestibility of sorghum stem. At a solid loading of 10% (w/v) and acid dosage of 0.25 g/g DM H₂SO₃ at 100 °C for 120 min, 44.5 g/L ethanol was obtained after 48 ± 4 h of simultaneous saccharification and fermentation. This corresponded to an overall ethanol yield of 110% of the theoretical one, based on the soluble carbohydrates in the fresh sweet sorghum stem. The concentrations of hydroxymethylfurfural and furfural of the sulfurous acid pretreated samples were below 0.4 g/L. Ethanol would not inhibit the cellulase activity, at least under the concentration of 34 g/L.     

Production of Lipids Containing High Levels of Docosahexaenoic Acid by a Newly Isolated Microalga, <Emphasis Type="Italic">Aurantiochytrium</Emphasis> sp. KRS101

In the present study, a novel oleaginous Thraustochytrid containing a high content of docosahexaenoic acid (DHA) was isolated from a mangrove ecosystem in Malaysia. The strain identified as an Aurantiochytrium sp. by 18S rRNA sequencing and named KRS101 used various carbon and nitrogen sources, indicating metabolic versatility. Optimal culture conditions, thus maximizing cell growth, and high levels of lipid and DHA production, were attained using glucose (60 g l⁻¹) as carbon source, corn steep solid (10 g l⁻¹) as nitrogen source, and sea salt (15 g l⁻¹). The highest biomass, lipid, and DHA production of KRS101 upon fed-batch fermentation were 50.2 g l⁻¹ (16.7 g l⁻¹ day⁻¹), 21.8 g l⁻¹ (44% DCW), and 8.8 g l⁻¹ (40% TFA), respectively. Similar values were obtained when a cheap substrate like molasses, rather than glucose, was used as the carbon source (DCW of 52.44 g l⁻¹, lipid and DHA levels of 20.2 and 8.83 g l⁻¹, respectively), indicating that production of microbial oils containing high levels of DHA can be produced economically when the novel strain is used.     

Utilization of Horticultural Waste for Laccase Production by <Emphasis Type="Italic">Trametes versicolor</Emphasis> Under Solid-State Fermentation

Horticultural waste collected from a landscape company in Singapore was utilized as the substrate for the production of laccase under solid-state fermentation by Trametes versicolor. The effects of substrate particle size, types of inducers, incubation temperature and time, initial medium pH value, and moisture content on laccase production were investigated. The optimum productivity of laccase (8.6 U/g substrate) was achieved by employing horticultural waste of particle size greater than 500 μm and using veratryl alcohol as the inducer. The culture was at 30 °C for 7 days at moisture content of solid substrate of 85% and initial pH 7.0. The decolorization was also investigated in order to assess the degrading capability of the ligninolytic laccase obtained in the above-mentioned cultures. The decolorization degree of a model dye, phenol red, was around 41.79% in 72 h of incubation. By far, this is the first report on the optimization of laccase production by T. versicolor under solid-state fermentation using horticultural waste as the substrate.     

Banana Peel: A Potential Substrate for Laccase Production by <Emphasis Type="Italic">Aspergillus fumigatus</Emphasis> VkJ2.4.5 in Solid-State Fermentation

In solid-state fermentation, among various solid supports evaluated, banana peel was found to be an ideal support and resulted into higher levels of laccase (6281.4 ± 63.60 U l⁻¹) along with notable levels of manganese peroxidase production (1339.0 ± 131.23 U l⁻¹) by Aspergillus fumigatus VkJ2.4.5. Maximum levels of laccase was achieved under derived conditions consisting of 80% of moisture level, 6 days of incubation period, 6% inoculum level, and an aeration level of 2.5 l min⁻¹. A column-tray bioreactor was designed to scale up and economize the enzyme production in three successive cycles of fermentation using the same fungal biomass. Thermal and pH stability profiles revealed that enzyme was stable up to 50°C and at varying pH range from 5–9 for up to 2 h. The apparent molecular weight of laccase was found to be 34 ± 1 kDa. MALDI-TOF/TOF analysis of the protein showed significant homology with maximum identity of 67% to other laccases reported in database.     

Microbial Production of Propionic Acid with <Emphasis Type="Italic">Propionibacterium freudenreichii</Emphasis> Using an Anion Exchanger-Based In Situ Product Recovery (ISPR) Process with Direct and Indirect Contact of Cells

The recovery of an inhibiting product from a bioreactor soon after its formation is an important issue in industrial bioprocess development. In the present study, the potential of the anion exchanger-based in situ product recovery (ISPR) technique for the biocatalytic production of propionic acid was discussed. The focus of the current work was the selection of a suitable configuration of metabolically active cells for application in propionic acid production. Accumulation of propionic acid in fermentation broth caused feedback inhibition of the growth and biotransformation activity of Propionibacterium freudenreichii CICC 10019. Relevant product inhibition kinetics was discussed, and the results showed that keeping the aqueous propionic acid concentration below 10.02 g L⁻¹ was an essential prerequisite for ISPR process. A batch study, in which three ISPR configuration mode designs were compared, was conducted. The comparison indicated that employing an external direct mode had significant advantages over other modes in terms of increased productivity and product yield, with a corresponding decrease in the number of downstream processing steps, as well as in substrate consumption. The fed-batch culture using an external direct mode for the continuous accumulation of propionic acid resulted in a cumulative propionic acid concentration of 62.5 g L⁻¹, with a corresponding product yield of 0.78 g propionic acid/g glucose.     

Production of Cellulolytic Enzymes by <Emphasis Type="Italic">Aspergillus phoenicis</Emphasis> in Grape Waste using Response Surface Methodology

The production of cellulolytic enzymes by the fungus Aspergillus phoenicis was investigated. Grape waste from the winemaking industry was chosen as the growth substrate among several agro-industrial byproducts. A 2 × 2 central composite design was performed, utilizing the amount of grape waste and peptone as independent variables. The fungus was cultivated in submerged fermentation at 30 °C and 120 rpm for 120 h, and the activities of total cellulases, endoglucanases, and β-glucosidases were measured. Total cellulases were positively influenced by the linear increase of peptone concentration and decrease at axial concentrations of grape waste and peptone. Maximum activity of endoglucanase was observed by a linear increase of both grape waste and peptone concentrations. Concentrations of grape waste between 5 and 15 g/L had a positive effect on the production of β-glucosidase; peptone had no significant effects. The optimum production of the three cellulolytic activities was observed at values near the central point. A. phoenicis has the potential for the production of cellulases utilizing grape waste as the growth substrate.     

Cellulases and Xylanases Production by <Emphasis Type="Italic">Penicillium echinulatum</Emphasis> Grown on Sugar Cane Bagasse in Solid-State Fermentation

To investigate the production of cellulases and xylanases from Penicillium echinulatum 9A02S1, solid-state fermentation (SSF) was performed by using different ratios of sugar cane bagasse (SCB) and wheat bran (WB). The greatest filter paper activity obtained was 45.82 ± 1.88 U gdm⁻¹ in a culture containing 6SCB/4WB on the third day. The greatest β-glucosidase activities were 40.13 ± 5.10 U gdm⁻¹ obtained on the third day for the 0SCB/10WB culture and 29.17 ± 1.06 U gdm⁻¹ for the 2SCB/8WB culture. For endoglucanase, the greatest activities were 290.47 ± 43.57 and 276.84 ± 15.47 U gdm⁻¹, for the culture 6SCB/4WB on the fourth and fifth days of cultivation, respectively. The greatest xylanase activities were found on the third day for the cultures 6SCB/4WB (36.38 ± 5.38 U gdm⁻¹) and 4SCB/6WB (37.87 ± 2.26 U gdm⁻¹). In conclusion, the results presented in this article showed that it was possible to obtain large amounts of cellulases and xylanases enzymes using low-cost substrates, such as SCB and WB.     

Production of α-amylase with Aspergillus oryzae on spent brewing grain by solid substrate fermentation

Ten Aspergillus oryzae strains were screened in solid substrate fermentation for α-amylase production on spent brewing grain (SBG) and on corn fiber. SBG proved to be a better substrate for enzyme production than corn fiber. A Plackett-Burman experimental design was used to optimize the medium composition for the best strain. Solid substrate fermentation on optimized medium with A. oryzae NRRL 1808 (=ATCC 12892) strain in stationary 500-mL Erlenmeyer flask culture yielded 4519 U of α-amylase/g of dry matter substrate in 3 d. The whole solid substrate fermentation material (crude enzyme, in situ enzyme) may be considered a cheap biocatalytic material for animal feed rations and for bioalcohol production from starchy materials.     

Butanol Production from Cane Molasses by <Emphasis Type="Italic">Clostridium saccharobutylicum</Emphasis> DSM 13864: Batch and Semicontinuous Fermentation

Clostridium acetobutylicum strains used in most Chinese ABE (acetone–butanol–ethanol) plants favorably ferment starchy materials like corn, cassava, etc., rather than sugar materials. This is one major problem of ABE industry in China and significantly limits the exploitation of cheap waste sugar materials. In this work, cane molasses were utilized as substrate in ABE production by Clostridium saccharobutylicum DSM 13864. Under optimum conditions, total solvent of 19.80 g/L (13.40 g/L butanol) was reached after 72 h of fermentation in an Erlenmeyer flask. In a 5-L bioreactor, total solvent of 17.88 g/L was attained after 36 h of fermentation, and the productivity and yield were 0.50 g/L/h and 0.33 g ABE/g sugar consumption, respectively. To further enhance the productivity, a two-stage semicontinuous fermentation process was steadily operated for over 8 days (205 h, 26 cycles) with average productivity (stage II) of 1.05 g/L/h and cell concentration (stage I) of 7.43 OD₆₆₀, respectively. The average batch fermentation time (stage I and II) was reduced to 21−25 h with average solvent of 15.27 g/L. This study provides valuable process data for the development of industrial ABE fermentation process using cane molasses as substrate.     

Production of Lipid and Fatty Acids during Growth of <Emphasis Type="Italic">Aspergillus terreus</Emphasis> on Hydrocarbon Substrates

An Aspergillus terreus, isolated from oil contaminated soil, could degrade a wide range of petroleum hydrocarbons including the immediate oxidation products of hydrocarbons, like alkanols and alkanals. Among all the linear chain carbon substrates, highest growth of 39.1 ± 3.8 g l⁻¹ (wet weight) was observed when n-hexadecane was used as the sole source of carbon. The growth of the fungus on this highly hydrophobic substrate was associated with the morphological change of the hyphae and increase production of lipid in the cells. The lipid production in the hydrocarbon (n-hexadecane) grown cells was sevenfold higher than the corresponding glucose grown cells. The fatty acid profile of the lipid content formed in the hydrocarbon grown cells was significantly different from the glucose grown cells and was composed of fatty acids with chain length C₁₄ to C₃₃ as revealed from the liquid chromatography electrospray ionization mass spectrometry analyses. Among the ranges, the fatty acids with chain lengths C₁₄ to C₁₈ were predominant in the profile. Considering the fatty acid profile and the high level of lipid production, this A. terreus mediated production of lipid is envisaged to have potential application in the oleochemical industries including the production of biodiesel.