Controlling filamentous fungi morphology with microparticles to enhanced β-mannanase production

Abstract

β-mannanase was produced mainly by Aspergillus species and can degrade the β-1,4-mannose linkages of galactomannans. This study was undertaken to enhance mannanase production using talcum and aluminum oxide as the microparticles, which control cell morphology of recombinant Aspergillus sojae in glucose and carob extract medium. Both microparticles improved fungal growth in glucose and carob pod extract medium. Aluminum oxide (1 g/L) was the best agent for glucose medium which resulted in 514.0 U/ml. However, the highest mannanase activity was found as 568.7 U/ml with 5 g/L of talcum in carob extract medium. Increase in microparticle concentration resulted in decreasing the pellet size diameter. Furthermore, more than 10 g/L of talcum addition changed the filamentous fungi growth type from pellet to pellet/mycelium mixture. Results showed that right type and concentration of microparticle in fermentation media improved the mannanase activity and production rate by controlling the growth morphology.

β‐Mannanase production and kinetic modeling from carob extract by using recombinant Aspergillus sojae

“…When talcum microparticles were inserted into the glucose‐ and carob extract‐based media, the enzyme activity was negatively affected in the glucose‐based media and the maximum activity was 199.3 U/mL with control fermentation (no‐added talcum) while it was reached to maximum (568.7 U/mL) by adding 5 g/L of talcum in carob extract‐based media (which was 1.83‐fold higher than control fermentation). Besides, when aluminum oxide as microparticle was used in the glucose‐ and carob extract‐based media, the enzyme activity increased to 514.0 U/mL and 343.6 U/mL by the addition of 1 g/L of aluminum oxide for both media, respectively, which was 2.58‐ and 1.11‐fold higher than control fermentation . In conclusion, higher β‐mannanase fermentation results were achieved under the optimized fermentation conditions (10°Bx initial sugar concentration, 0.75% (w/v) whey concentration as an organic nitrogen source, and 8% (v/v) inoculum size) when compared with the existing results in the literature.…”

“…On the other hand, the effects of different nitrogen sources (pure nitrogen sources: yeast extract, beef extract, and ammonium nitrate; animal by‐products: meat bone meal, feather meal, and fish meal; and vegetable by‐products: red lentil, cotton seed meal, maize zein, and soybean meal) on β‐mannanase fermentation were also examined by Yatmaz et al, who reported that the highest β‐mannanase activities were found to be 695.6 U/mL with 0.5% of ammonium nitrate that is a pure nitrogen source, 597.31 U/mL with 0.75% of meat bone meal that is an animal by‐product, and 525.93 U/mL with 0.75% of soybean meal that is a vegetable nitrogen source . As a different study, β‐mannanase fermentations in glucose‐ and carob extract‐based media were performed by adding talcum and aluminum oxide microparticles into the fermentation medium to control the fungal morphology . When talcum microparticles were inserted into the glucose‐ and carob extract‐based media, the enzyme activity was negatively affected in the glucose‐based media and the maximum activity was 199.3 U/mL with control fermentation (no‐added talcum) while it was reached to maximum (568.7 U/mL) by adding 5 g/L of talcum in carob extract‐based media (which was 1.83‐fold higher than control fermentation).…”

“…Fermentations were carried out at 30°C temperature and at 200 rpm agitation speed for 8 days. Samples were collected every 2 days and analyzed for enzyme activity and sugar concentration, which were stored at 4°C until analyzed …”

“…However, an adequate amount of enzymes from animal and plant sources is not an economic and practical approach for the enzyme industry. Thereby, the enzyme industry utilizes the microorganisms to generate the specific enzymes or enzyme mixtures, and thus the microbial enzymes are recognized globally because of their widespread use in various industries . Enzyme‐mediated processes are of interest owing to their low processing time, low energy intake, cost‐effectiveness, nontoxicity, and environmentally friendly features.…”

Inulinase production and mathematical modeling from carob extract by using Aspergillus niger

“…9,30,31 Besides, total protein analysis was carried out with ThermoScientific Coomassie (Bradford) Protein Assay Kit using bovine serum albumin solution (2 mg/ml) as a standard to determine specific inulinase and specific invertase-type activities. One unit of the enzyme activity (1 U = 16.7 nanokatal) was defined as the amount of that releases the reducing sugar equal to 1 μMe of β-D-fructose from inulin or sucrose (2%, wt/vol) in Na-acetate buffer (100 mM) at pH 4.8 and 60 C per min.…”