Characteristics of pectate lyase formation by Hypomyces solani f. sp. cucurbitae

1970 ◽  
Vol 16 (2) ◽  
pp. 69-74 ◽  
Author(s):  
Joseph G. Hancock ◽  
Colleen Eldridge ◽  
Michal Alexander

Pectate lyase, produced by Hypomyces (Fusarium) solani f. sp. cucurbitae, is considered a normal extracellular enzyme in that most of the enzyme was found in the culture medium during early stages of enzyme production and before extensive lysis. This enzyme was produced during active growth in the presence of citrus pectate but not citrus pectin. Enzyme yield was highest when the initial pH of the medium was between 5.5 and 7.5 and the temperature was between 25 and 29 C. Production of the enzyme was reduced when individual amino acids or inorganic N-sources were substituted for casein hydrolyzates. Glucose repressed enzyme formation when it exceeded 0.025%, while arabinose and xylose had little effect or stimulated greater production at 0.1%. Pectate lyase yield varied considerably, depending on fungus strain and inoculum level used. A delay in enzyme formation was reduced substantially when small amounts of agar were present in the liquid medium or the medium was solidified with agar.

2019 ◽  
Vol 45 (2) ◽  
pp. 141-145 ◽  
Author(s):  
Ricardo Mezzomo ◽  
Jéssica Mengue Rolim ◽  
Álvaro Figueredo dos Santos ◽  
Tales Poletto ◽  
Clair Walker ◽  
...  

ABSTRACT The yerba-mate (Ilex paraguariensis) has great socioeconomic importance on family farming in Southerm Brazil. One of the main yerba-mate disease is root rotting, caused by Fusarium spp. Little is known about the pathogen physiology, especially regarding the aggressiveness associated with the production of extracellular enzymes. On this work, the aggressiveness of isolates of F. oxysporum and F. solani pathogenic to yerba-mate was evaluated and it was determined the activities of extracellular enzymes catalase, laccase, cellulase, caseinase, amylase, protease, lipase and pectinases produced by Fusarium spp. in culture medium. Six isolates of F. solani and one isolate of F. oxysporum pathogenic to yerba-mate were used. The F. oxysporum isolate proved to be less aggressive in relation to the other F. solani isolates. All isolates of Fusarium spp. produced, on a semiquantitative manner, the extracellular enzymes catalase, laccase, cellulase, caseinase, amylase, protease, lipase and pectinases (polygalacturonase and pectate lyase). However, the quantity produced for each enzyme was significantly different among the isolates. With the exception of the laccase and polygalacturonase enzymes, the M7C1 isolate showed the highest enzymatic index and was also responsible for the highest percentage of yerba-mate seedlings death.


1955 ◽  
Vol 1 (5) ◽  
pp. 299-311 ◽  
Author(s):  
R. Steel ◽  
C. P. Lentz ◽  
S. M. Martin

Factors affecting the production of citric acid in the submerged fermentation of ferrocyanide-treated beet molasses by Aspergillus niger were studied in 2.5 and 36 liter fermenters. The small fermenters were used to determine the effects of changes in sterilization technique, phosphate supplement, ferrocyanide treatment, inoculum level, initial pH, fermentation temperature, and aeration rate. The relation between ferrocyanide concentration and inoculum level was also studied. Four different samples of molasses were fermented successfully. An average yield of 8.2% citric acid (64% conversion) was obtained from 51 small-scale fermentations. Comparable yields were obtained in the large fermenters under comparable conditions. Most of the information obtained with the small fermenters was applicable to the larger-scale fermenters, but in the latter the fermentation was significantly more stable. Aeration was the main problem in the scale-up and aeration rates approximately double those calculated on a fermenter cross-sectional area basis were required for comparable results in the large fermenters.


2011 ◽  
Vol 175-176 ◽  
pp. 192-196 ◽  
Author(s):  
Li Li Feng ◽  
Jian Fei Zhang ◽  
Hui Luo ◽  
Zheng Li ◽  
Hong Jie Zhang

The paper concentrated on the optimization of the recombinant strain BL21 (DE3)-PE7-Nit. The component of culture medium and the culture conditions were optimized. The optimized medium was: yeast extract 10 g/l, L-glutamate sodium 8 g/l, MgSO4.7H2O 0.7 g/l, Isopropyl-β-D-thiogalactopyranoside 0.3 mmol/L, potassium hydrogen phosphate 0.5 g / L, phosphate Potassium 0.5 g / L and the culture condition was: initial pH 7.0, inoculum 2%. The result showed that the activity of nitrilase prepared with these conditions increased by 130.37 % through optimization.


Molecules ◽  
2018 ◽  
Vol 23 (11) ◽  
pp. 2774 ◽  
Author(s):  
Yan Zhao ◽  
Ye Yuan ◽  
Xinyu Zhang ◽  
Yumei Li ◽  
Qiang Li ◽  
...  

Pectate lyase (EC 4.2.2.2) catalyzes the cleavage of α-1,4-glycosidic bonds of pectin polymers, and it has potential uses in the textile industry. In this study, a novel pectate lyase belonging to polysaccharide lyase family 10 was screened from the secreted enzyme extract of Paenibacillus polymyxa KF-1 and identified by liquid chromatography-MS/MS. The gene was cloned from P. polymyxa KF-1 genomic DNA and expressed in Escherichia coli. The recombinant enzyme PpPel10a had a predicted Mr of 45.2 kDa and pI of 9.41. Using polygalacturonic acid (PGA) as substrate, the optimal conditions for PpPel10a reaction were determined to be 50 °C and pH 9.0, respectively. The Km, vmax and kcat values of PpPel10a with PGA as substrate were 0.12 g/L, 289 μmol/min/mg, and 202.3 s−1, respectively. Recombinant PpPel10a degraded citrus pectin, producing unsaturated mono- and oligogalacturonic acids. PpPel10a reduced the viscosity of PGA, and weight loss of ramie (Boehmeria nivea) fibers was observed after treatment with the enzyme alone (22.5%) or the enzyme in combination with alkali (26.3%). This enzyme has potential for use in plant fiber processing.


There are numerous previous studies working on biosynthesis, properties and applications of bacterial cellulose (BC) membrane from Acetobacter xylinum bacteria strain. However, there is less research examining the effect of initial pH level on BC membrane properties. Here, BC membranes were produced at different pH level (concentration of acetic acid) of coconut water-based culture medium which are 3.5, 4.0, 4.5, 5.0 and 5.5 for 7 days, statically. The effect of initial pH level during BC production on morphology, physical and characteristics were investigated. The Acetobacter xylinum membrane were studied its crystallinity using X-ray diffraction, FTIR analysis for chemical structure and FESEM for morphological analysis. In addition, the different of initial pH level does affect the membrane yield and breathability properties using an Upright Cup Method of water vapour permeability testing. Although certain suitable amount of acid had reduced the production yield, a breathable BC membrane was produced.


2018 ◽  
Vol 43 (3) ◽  
pp. 240-247 ◽  
Author(s):  
Nurullah Akcan

AbstractObjective:The aim of this work was to study the optimal cultivation conditions for β-galactosidase production byBacillus licheniformisATCC 12759.Materials and methods:The screening of β-galactosidase production fromB. licheniformisATCC 12759 was performed by solid state fermentation method on media rich with rice bran (RB). Different factors were tested for the optimization of β-galactosidase production.Results:Certain fermentation parameters involving incubation time, incubation temperature, inoculum level, moisture content, initial pH, agitation speed, size of fermentation medium and optimum temperature of β-galactosidase activity were studied separately. Maximal amount of β-galactosidase production was obtained when solid-state fermentation (SSF) was carried out using RB, having inoculum level 35%, moisture content of 20%, initial pH 7.5 at 37°C for 48 h.Conclusion:Results indicated that optimal fermentation conditions play a key role in the maximum production of β-galactosidase fromB. licheniformisATCC 12759. This study shows the potential of the studied enzymes to be promoting candidates for the degradation of lactose and production of important bioproducts.


Author(s):  
Whallans Raphael Couto Machado ◽  
Lucas Gomes da Silva ◽  
Ellen Silva Lago Vanzela ◽  
Vanildo Luiz Del Bianchi

Abstract This study aimed to improve the physical and nutritional process conditions for the production of carotenoids by the newly isolated Rhodotorula mucilaginosa, a red basidiomycete yeast. The carotenoid bioproduction was improved using an experimental design technique, changing the process characteristics of agitation (130 rpm to 230 rpm) and temperature (25 °C to 35 °C) using seven experiments, followed by a 25-1 fractional design to determine the relevant factors that constitute the culture medium (glucose, malt extract, yeast extract, peptone and initial pH). A complete second order experimental design was then carried out to optimize the composition of the culture medium, the variables being yeast extract (0.5 to 3.5 g/L), peptone (1 to 5 g/L) and the initial pH (5.5 to 7.5), with 17 experiments. The maximum carotenoid production was 4164.45 μg/L (252.99 μg/g), obtained in 144 h in YM (yeast malt) medium with 30 g/L glucose, 10 g/L malt extract, 2 g/L yeast extract, 3 g/L peptone, an initial pH 6, 130 rpm and 25 °C, demonstrating the potential of this yeast as a source of bio-pigments. In this work, the nitrogen sources were the factors that most influenced the intracellular accumulation of carotenoids. The yeast R. mucilaginosa presented high production at a bench level and may be promising for commercial production.


2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Zhu Li ◽  
Lingqia Su ◽  
Xuguo Duan ◽  
Dan Wu ◽  
Jing Wu

The maltohexaose-forming, Ca2+-independent α-amylase gene from Bacillus stearothermophilus (AmyMH) was efficiently expressed in Brevibacillus choshinensis SP3. To improve the production of AmyMH in B. choshinensis SP3, the temperature and initial pH of culture medium were optimized. In addition, single-factor and response surface methodologies were pursued to optimize culture medium. Addition of proline to the culture medium significantly improved the production of recombinant α-amylase in B. choshinensis SP3. This improvement may result from improved cellular integrity of recombinant B. choshinensis SP3 in existence of proline. Culture medium optimization resulted in an 8-fold improvement in α-amylase yield, which reached 1.72 × 104 U·mL−1. The recombinant α-amylase was applied to the production of maltose on a laboratory scale. A maltose content of 90.72%, which could be classified as an extremely high maltose syrup, could be achieved using 15% (m/v) corn starch as the substrate. This study demonstrated that the B. choshinensis SP3 expression system was able to produce substantial quantities of recombinant α-amylase that has potential application in the starch industry.


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