Lytic enzyme production optimization using low‐cost substrates and its application in the clarification of xanthan gum culture broth

Abstract

Lytic enzymes are widely used in industrial biotechnology as they are able to hydrolyze the bacterial cell wall. One application of these enzymes is the clarification of the culture broth for the production of xanthan gum, because of its viability in viscous media and high specificity. The screening process for filamentous fungi producing lytic enzymes, the optimization of production of these enzymes by the selected microorganism, and the optimization of the application of the enzymes produced in the clarification of culture broth are presented in this article. Eleven fungal isolates were tested for their ability to produce enzymes able to increase the transmittance of the culture broth containing cells of Xanthomonas campestris. To optimize the secretion of lytic enzymes by the selected microorganism the following variables were tested: solid substrate, initial pH, incubation temperature, and addition of inducer (gelatin). Thereafter, secretion of the enzymes over time of incubation was assessed. To optimize the clarification process a central composite rotational design was applied in which the pH of the reaction medium, the dilution of the broth, and the reaction temperature were evaluated. The isolate identified as Aspergillus tamarii was selected for increasing the transmittance of the broth from 2.1% to 54.8%. The best conditions for cultivation of this microorganism were: use of coconut husk as solid substrate, with 90% moisture, at 30°C for 20 days. The lytic enzymes produced thereby were able to increase the transmittance of the culture broth from 2.1% to 70.6% at 65°C, without dilution and without pH adjustment.

Enhanced production of fibrinolytic enzyme by a new Xanthomonas oryzae IND3 using low-cost culture medium by response surface methodology

“…zinniae (Sun, 1991), Xanthomonas sp. (Silva et al, 2014), and Xanthomonas campestris (Dow et al, 1993). Recently, proteolytic enzyme was characterized from Xanthomonas campestris pv.…”

“…punicae strain has the ability to produce xylanolytic and cellulolytic enzymes (Amat et al, 2014). Lytic enzyme was produced from Xanthomonas campestris using low cost substrates (Da Silva et al, 2014). Kalashnikova et al (2003) used three Xanthomonas campestris pv.…”

Fermentation of Multi-Targeted Products: A statistical Approach Discussed the Production of Cell Wall Hydrolytic Enzymes from Streptomyces rochei for Pathogenic Fungi biocontrol

“…These results indicated that lytic enzymes (protease, glucanase and chitinase) acted synergistically to digest the cell wall of C. albicans [1]and this effect started with protease which cleave cell wall protein and open it to expose the inner layer of glucan and chitin to be attacked by glucanase and chitinase forming a big hole in the cell wall giving a protoplast which can be lyses immediacy releasing the cell constituents [3]. Thus this multi-enzyme system can be applied for biological control [4,40].…”

Microbial production of poly(hydroxyalkanoates) and biorefinery development using by-product streams from sunflower-based biodiesel production processes

“…The cell wall of gram-negative bacteria is composed of a peptidoglycan layer surrounded by an outer membrane, consisting mainly of proteins, phospholipids, lipoproteins and lipopolysaccharides (da Silva et al, 2012). Gram-negative bacteria are resistant to enzymatic lysis by lytic enzymes that hydrolyse only the peptidoglycan layer, such as lysozymes and murein hydrolases.…”

“…Therefore, the effective lysis of the cell wall of gram-negative bacteria can be accomplished by the combination of various enzymes, such as amidase, lipase and protease. Filamentous fungi can produce a combination of enzymes required for the lysis of the cell wall of gram-negative bacteria (da Silva et al, 2012). Tsakona et al (2016) showed that crude enzymes preparation produced via solid state fermentation of Aspergillus awamori could be used for the lysis of oleaginous yeast cells leading to the release of microbial oil that is originally produced as an intracellular product.…”