Enhanced xylan degradation and utilisation by Pichia stipitis overproducing fungal xylanolytic enzymes

2003 ◽  
Vol 33 (5) ◽  
pp. 620-628 ◽  
Author(s):  
R. Den Haan ◽  
W.H. Van Zyl
Keyword(s):  
Pichia Stipitis ◽  
Xylan Degradation ◽  
Xylanolytic Enzymes

scholarly journals The Transcriptional Activator XlnR Regulates Both Xylanolytic and Endoglucanase Gene Expression inAspergillus niger

1998 ◽  
Vol 64 (10) ◽  
pp. 3615-3619 ◽  
Author(s):  
Noël N. M. E. van Peij ◽  
Marco M. C. Gielkens ◽  
Ronald P. de Vries ◽  
Jaap Visser ◽  
Leo H. de Graaff
Keyword(s):  
Cellulose Degradation ◽  
Mrna Level ◽  
Transcriptional Activator ◽  
Feruloyl Esterase ◽  
Loss Of Function ◽  
Gene Encoding ◽  
Xylan Degradation ◽  
Genes Encoding ◽  
Encoding Genes ◽  
Xylanolytic Enzymes

ABSTRACT The expression of genes encoding enzymes involved in xylan degradation and two endoglucanases involved in cellulose degradation was studied at the mRNA level in the filamentous fungusAspergillus niger. A strain with a loss-of-function mutation in the xlnR gene encoding the transcriptional activator XlnR and a strain with multiple copies of this gene were investigated in order to define which genes are controlled by XlnR. The data presented in this paper show that the transcriptional activator XlnR regulates the transcription of thexlnB, xlnC, and xlnD genes encoding the main xylanolytic enzymes (endoxylanases B and C and β-xylosidase, respectively). Also, the transcription of the genes encoding the accessory enzymes involved in xylan degradation, including α-glucuronidase A, acetylxylan esterase A, arabinoxylan arabinofuranohydrolase A, and feruloyl esterase A, was found to be controlled by XlnR. In addition, XlnR also activates transcription of two endoglucanase-encoding genes, eglA andeglB, indicating that transcriptional regulation by XlnR goes beyond the genes encoding xylanolytic enzymes and includes regulation of two endoglucanase-encoding genes.

XYLANASE, AN ENVIRONMENTALLY FRIENDLY BLEACHING AGENT FOR PULP AND PAPER: Characterization And Stabilization Study Of Bacillus licheniformis I-5 CRUDE Xylanase

2018 ◽  
Vol 7 (3) ◽  
Author(s):  
Budiasih Wahyuntari., dkk
Keyword(s):  
Thermal Stability ◽  
Bacillus Licheniformis ◽  
Hot Spring ◽  
Sodium Dodecyl ◽  
Luria Broth ◽  
Crude Enzyme ◽  
Half Time ◽  
Triton X100 ◽  
Sds Page ◽  
Xylanolytic Enzymes

Isolate I-5 was isolated from Ciseeng hot spring, West Java and was identified as Bacillus licheniformis I-5. The isolate produces extracellular xylanolytic enzymes on Oatspelt containing Luria broth agar medium. Optimal activity of the crude enzyme was  observed at 50ºC and pH 7. The effect of sodium dodecyl sulphate, b-mercaptoethanol and Triton-X100 were observed. Incubating the crude enzyme in 1.5% SDS and 1.5% b-mercaptoethanol at 50oC for 90 minutes then adding Triton-X100 at final concentration of 3.5% for 45 minutes only reduced 5.75% of the initial enzyme activity. SDS/PAGE and zymogram analysis showed that at least two xylanolytic enzymes presence in the crude enzyme. The molecular weight of the enzyme was estimated about 127 and 20kD. The enzyme hydrolysed xylan into xylobiose, xylotriose and other longer xylooligosaccharides. Thermal stability of the crude enzyme was observed at 50, 60, and 70oC and pH 7 and 8. The results showed that the half time of the crude enzyme incubated at 50, 60, and 70oC pH 7 was 2 hours 55 minutes; 2 hours 33 minutes and 1 hour 15 minutes respectively. The half time at 50, 60 and 70oC, pH 8 was 2 hours 48 minutes; 1 hour 22 minutes and 1 hour 9 minutes respectively.keywords: Xilanase, Bacillus licheniformis I-5, thermal stability

Structural and mechanistic insight into stem‐loop RNA processing by yeast Pichia stipitis Dicer

2021 ◽  
Author(s):  
Chan Jing Ru ◽  
Fu Qinqin ◽  
Li Jianwei ◽  
Chen Ying ◽  
Satoru Machida ◽  
...  
Keyword(s):  
Rna Processing ◽  
Pichia Stipitis ◽  
Stem Loop ◽  
Mechanistic Insight ◽  
Insight Into

Ethanol Production from Corn Stover Using Soaking Pretreatment

2010 ◽  
Vol 171-172 ◽  
pp. 261-265
Author(s):  
Zhuang Zuo ◽  
Xiu Shan Yang
Keyword(s):  
Ethanol Production ◽  
Corn Stover ◽  
Simultaneous Saccharification And Fermentation ◽  
Pichia Stipitis ◽  
Liquid Ratio ◽  
Mild Conditions ◽  
Whole Process ◽  
Conversion Rates ◽  
Mild Temperature ◽  
Simultaneous Saccharification

Corn stover was pretreated using different soaking conditions at mild temperature. Among the tested conditions, the best was 1% NaOH+8% NH4OH，50°C，48 h, Solid-to-liquid ratio 1:10. The results showed that soaking pretreatment achieved 63.6% delignification, retained the xylan and glucan. After enzymatic hydrolysis, conversion rates of xylan and glucan were 70.9% and 78.5%, respectively. The pretreated filtration re-soaking cause 52.7% xylan and 65.0% glucan conversion. NaOH+NH4OH treatment can be performed under mild conditions, gives a good buffering effect, low carbohydates degradation and extensive removal of lignin. Additionally, simultaneous saccharification and fermentation was conducted with pretreated corn stover to assess the ethanol production. For the whole process, 0.15g ethanol /g corn stover was achieved using Saccharomyces cerevisiae Y5, and 0.19g ethanol /g corn stover when using Pichia stipitis.

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