Stable release of enhanced organic solvent tolerant amylase from Bacillus amyloliquefaciens AMY02 under sub-merged fermentation

552-559This study has been performed to isolate a potential strain able to release the prolific amylase under non-aqueous conditions to meet the current demand in industries to substitute the amylase produced in aqueous media. A bacterial strain that produces organic solvent-stable amylase in the media containing 15% benzene was isolated from the soil. The recovered strain was identified to be Bacillus amyloliquefaciens AMY02by 16S rRNA sequencing. Under sub-merged fermentation, the optimized amylase release by this strain was found with the condition having starch (carbon source), pH 7.0, the temperature at 30°C for 48 h (incubation time). This optimized condition promoted the amylase production to be 2.04-fold higher than the culture was kept under standard condition with the basic media composition. Further, the stability of the enzyme in the presence of 20% organic solvents was assessed by incubating for 2 weeks. The enzyme was found to be active and stable in the presence of benzene, chloroform, o-xylene, and toluene. The higher organic solvent stability of this amylase production by B. amyloliquefaciens under sub-merged fermentation can be an alternative catalyst in non-aqueous media for industrial applications

Stable release of enhanced organic solvent tolerant amylase from Bacillus amyloliquefaciens AMY02 under sub-merged fermentation

This study has been performed to isolate a potential strain able to release the prolific amylase under non-aqueous conditions to meet the current demand in industries to substitute the amylase produced in aqueous media. A bacterial strain that produces organic solvent-stable amylase in the media containing 15% benzene was isolated from the soil. The recovered strain was identified to be Bacillus amyloliquefaciens AMY02by 16S rRNA sequencing. Under sub-merged fermentation, the optimized amylase release by this strain was found with the condition having starch (carbon source), pH 7.0, the temperature at 30°C for 48 h (incubation time). This optimized condition promoted the amylase production to be 2.04-fold higher than the culture was kept under standard condition with the basic media composition. Further, the stability of the enzyme in the presence of 20% organic solvents was assessed by incubating for 2 weeks. The enzyme was found to be active and stable in the presence of benzene, chloroform, o-xylene, and toluene. The higher organic solvent stability of this amylase production by B. amyloliquefaciens under sub-merged fermentation can be an alternative catalyst in non-aqueous media for industrial applications

Encapsulation of fungal extracellular enzyme cocktail in cellulose nanoparticles: enhancement in enzyme stability

We demonstrated the nano-immobilization of fungal enzymes through their encapsulation in cellulose nanoparticles (CNPs). An extracellular enzyme cocktail (a mixture of amylase, protease, lipase, and cellulose) was produced from Aspergillus niger and Phanerochaete chrysosporium through submerged fermentation. The process of encapsulation was carried out through a microemulsion nanoprecipitation method in the presence of a lipid, a surfactant, and a co-surfactant. The morphology of CNPs was determined by field-emission scanning electron microscopy and transmission electron microscopy; CNPs were less than 100 nm in diameter. Fourier transform infrared spectroscopy (FTIR) and energy dispersive spectroscopy demonstrated the successful encapsulation of the fungal enzyme cocktail and revealed C and O as its major components. FTIR peaks of CNPs with encapsulated enzymes occurred at 3421.80, 2828.91, 1649.29, 1450.24, and 1061.61 cm−1 as well as in the range of 1050–1150 cm−1. Encapsulated enzymes showed excellent stability with a peak at −70.91 mV in zeta potential studies. Thermogravimetric analysis proved that the CNP-encapsulated enzymes had an initial weight loss at 250C. The encapsulated fungal enzyme cocktail exhibited higher catalytic performance and stability than the free enzymes. The encapsulated fungal enzyme cocktail derived from A. niger at the concentration of 100 µg/mL, showed the highest amylase activity with a clear zone of 2.5 cm. Overall, the results of this research reveal the enhancement in the activity of fungal extracellular enzyme cocktail through nanoencapsulation

Amino acid analysis of lipases from oil pollutant isolates: Cunninghamella verticillata and Geotrichum candidum

Lipase is an enzyme commonly used in food, dairy, and other industries. Fungal lipases are more commonly used due to their secretion and easier production. Analyses of the amino acid composition of microbial lipases will hasten their potential usage in industrial applications. In this study, the major amino acid compositions of lipases secreted by oil pollutant isolates (Cunninghamella verticillata and Geotrichum candidum) enriched with fatty substances were analyzed by high performance liquid chromatography. Among eight major amino acids found in these lipases, histidine and ornithine were predominant. Lysine was absent from lipase generated by C. verticillata, while glutamine was absent from that produced by G. candidum. Conversely, glutamic acid, asparagine, histidine and arginine were present in slightly higher amounts in G. candidum. However, a slight decrease in aspartic acid and ornithine was observed in G. candidum. Analyses of the amino acids composition of lipase can potentially facilitate to predict the nature of this enzyme

Strategies to Characterize Fungal Lipases for Applications in Medicine and Dairy Industry

Lipases are water-soluble enzymes that act on insoluble substrates and catalyze the hydrolysis of long-chain triglycerides. Lipases play a vital role in the food, detergent, chemical, and pharmaceutical industries. In the past, fungal lipases gained significant attention in the industries due to their substrate specificity and stability under varied chemical and physical conditions. Fungal enzymes are extracellular in nature, and they can be extracted easily, which significantly reduces the cost and makes this source preferable over bacteria. Soil contaminated with spillage from the products of oil and dairy harbors fungal species, which have the potential to secrete lipases to degrade fats and oils. Herein, the strategies involved in the characterization of fungal lipases, capable of degrading fatty substances, are narrated with a focus on further applications

Secretion of 2,4 di-tertbutylphenol by a new Pseudomonas strain SBMCH11: A tert-butyl substituted phenolic compound displayed antibacterial efficacy

Pseudomonas sp. SBMCH11 was newly isolated from maritime soil samples which was identified by morphological, biochemical, and 16S rRNA gene sequencing. The isolated Pseudomonas sp. SBMCH11 had significant antibacterial activity against clinical bacterial strains including Pseudomonas aeruginosa and Staphylococcus aureus. Subsequently, high concentrations of antibacterial substances were achieved by optimizing the following parameters: pH (7.0), carbon (1 %), nitrogen sources (casein 0.2 %), NaCl (10 %), and incubation time (120 hrs). Furthermore, the extracted component from the Pseudomonas sp. SBMCH11 was shown to have a significant inhibitory effect on tested clinical pathogens. On the other hand, the extracted compound was confirmed as 2,4 di-tertbutylphenol (2,4 DTBP) by GC–MS with a molecular weight of 206.5 Daltons. Based on these findings, the isolated 2,4 DTBP could be recognized as a promising bioactive molecule for further antibacterial medication development. Compounds identified in the maritime environment from microorganisms, especially Pseudomonas sp. SBMCH11 could be regarded as a potential bio-factory for the synthesis of antibacterial compounds to suppress large numbers of pathogenic bacteria in the natural environment

Electro-determination of protonation by tungsten anchored carbon nanoparticle on interdigitated gold electrode

This study presented an enhanced sensitivity of sensing protons (H+) by anchoring tungsten to carbon nanoparticles (WCN) to encourage high current density on the surface of gold interdigitated electrode (AuIDE). The morphology of the sensor evidences the intactness of electrode surface and suitable for WCN modification. To elucidate the study, unmodified AuIDE was compared to the WCN modified surface. Current-volt analysis was compared with electrolyte scouting in the variation of pH by using a picoammater, which supplied 0.0 to 2.0 V with a 0.1 V ramp interval. It was shown that modified WCN gave the sensitivity in the acidic medium (protons) at the pH 4 with a current density value of 2.5 × 10-5 ampere and increased further with lowering the pH to more acidic. This is due to the fact that the tungsten carbon nanoparticle that is anchored offering more electron density and alters the behavior of the chip. Meanwhile, the current density displayed insignificant changes of current density amplification from pH 5 to 12 with the range of 5.91 × 10-9 to 7.36 × 10-8 Ampere. The deposition of WCN on the AuIDE surface chip revealed the successfulness of this nanoparticle in chemically linked with the AuIDE surface and how modified nanoparticle altered the behavior of the sensing element