Lignin Degradation by Microorganisms: A Review

2021 ◽  
Author(s):  
Ghada Atiwesh ◽  
Christopher C. Parrish ◽  
Joseph Banoub ◽  
Tuyet‐Anh T. Le
Keyword(s):  
2021 ◽  
Vol 22 (12) ◽  
pp. 6557
Author(s):  
Li-Ying Ren ◽  
Heng Zhao ◽  
Xiao-Ling Liu ◽  
Tong-Kai Zong ◽  
Min Qiao ◽  
...  

Gastrodia elata is a well-known medicinal and heterotrophic orchid. Its germination, limited by the impermeability of seed coat lignin and inhibition by abscisic acid (ABA), is triggered by symbiosis with fungi such as Mycena spp. However, the molecular mechanisms of lignin degradation by Mycena and ABA biosynthesis and signaling in G. elata remain unclear. In order to gain insights into these two processes, this study analyzed the transcriptomes of these organisms during their dynamic symbiosis. Among the 25 lignin-modifying enzyme genes in Mycena, two ligninolytic class II peroxidases and two laccases were significantly upregulated, most likely enabling Mycena hyphae to break through the lignin seed coats of G. elata. Genes related to reduced virulence and loss of pathogenicity in Mycena accounted for more than half of annotated genes, presumably contributing to symbiosis. After coculture, upregulated genes outnumbered downregulated genes in G. elata seeds, suggesting slightly increased biological activity, while Mycena hyphae had fewer upregulated than downregulated genes, indicating decreased biological activity. ABA biosynthesis in G. elata was reduced by the downregulated expression of 9-cis-epoxycarotenoid dioxygenase (NCED-2), and ABA signaling was blocked by the downregulated expression of a receptor protein (PYL12-like). This is the first report to describe the role of NCED-2 and PYL12-like in breaking G. elata seed dormancy by reducing the synthesis and blocking the signaling of the germination inhibitor ABA. This study provides a theoretical basis for screening germination fungi to identify effective symbionts and for reducing ABA inhibition of G. elata seed germination.


2021 ◽  
Vol 53 (3) ◽  
Author(s):  
Qingbiao Xu ◽  
Huimin Zhong ◽  
Jiayan Zhou ◽  
Yong Wu ◽  
Zhenhua Ma ◽  
...  

Holzforschung ◽  
1982 ◽  
Vol 36 (2) ◽  
pp. 85-91 ◽  
Author(s):  
Annegret Haars ◽  
Oleg Milstein ◽  
Sigrun Lohner ◽  
Aloys Hüttermann
Keyword(s):  

2010 ◽  
Vol 101 (11) ◽  
pp. 4062-4067 ◽  
Author(s):  
Dan-Lian Huang ◽  
Guang-Ming Zeng ◽  
Chong-Ling Feng ◽  
Shuang Hu ◽  
Cui Lai ◽  
...  

2011 ◽  
Vol 91 (4) ◽  
pp. 695-702 ◽  
Author(s):  
J. E. Ramirez-Bribiesca ◽  
Y. Wang ◽  
L. Jin ◽  
T. Canam ◽  
J. R. Town ◽  
...  

Ramirez-Bribiesca, J. E., Wang, Y., Jin, L., Canam, T., Town, J. R., Tsang, A., Dumonceaux, T. J. and McAllister, T. A. 2011. Chemical characterization and in vitro fermentation of Brassica straw treated with the aerobic fungus, Trametes versicolor . Can. J. Anim. Sci. 91: 695–702. Brassica napus straw (BNS) was either not treated or was treated with two strains of Trametes versicolor; 52J (wild type) or m4D (a cellobiose dehydrogenase-deficient mutant) with four treatments: (i) untreated control (C-BNS), (ii) 52J (B-52J), (iii) m4D (B-m4D) or (iv) m4D+glucose (B-m4Dg). Glucose was provided to encourage growth of the mutant strain. All treatments with T. versicolor decreased (P<0.05) neutral-detergent fibre and increased (P<0.05) protein and the concentration of lignin degradation products in straw. Ergosterol was highest (P<0.05) in straw treated with B-52J, suggesting it generated the most fungal biomass. Insoluble lignin was reduced (P<0.05) in straw treated with B-52J and B-m4D, but not with B-m4Dg. Mannose and xylose concentration were generally higher (P<0.05) in straw treated with fungi, whereas glucose and galactose were lower as compared with C-BNS. The four treatments above were subsequently assessed in rumen in vitro fermentations, along with BNS treated with 2 mL g−1of 5 N NaOH. Concentrations of total volatile fatty acids after 24 and 48h were lower (P<0.05) in incubations that contained BNS treated with T. versicolor as compared with C-BNSor NaOH-treated BNS. Compared with C-BNS, in vitrodry matter disappearance and gas production were increased (P<0.05) by NaOH, but not by treatment with either strain of T. versicolor. Although treatment with T. versicolor did release more lignin degradation products, it did not appear to provide more degradable carbohydrate to in vitro rumen microbial populations, even when a mutant strain with compromised carbohydrate metabolism was utilized. Production of secondary compounds by the aerobic fungi may inhibit rumen microbial fermentation.


1995 ◽  
Vol 6 (4) ◽  
pp. 265-274 ◽  
Author(s):  
Andr� Ferraz ◽  
Nelson Dur�n
Keyword(s):  

Holzforschung ◽  
2008 ◽  
Vol 62 (2) ◽  
pp. 183-188 ◽  
Author(s):  
Krishna K. Pandey ◽  
Tapani Vuorinen

Abstract The effect of laser irradiation (Ar+ ion laser, 244 nm) on photodegradation of lignin in silver birch and rubberwood as hardwoods and spruce and chir pine as softwoods has been investigated by UV resonance Raman spectroscopy (UVRRS). UVRR spectra showed degradation of aromatic structures accompanied by the formation of both ortho- and para-quinone structures as a result of photodegradation of wood surfaces. There was a rapid decrease in the intensities of all the lignin-associated bands accompanied by broadening of aromatic bands at 1602 cm-1 and in the region of 1500–1000 cm-1 due to formation of unsaturated structures arisen from lignin degradation. The rate of lignin degradation was observed by measuring the relative intensity of aromatic band at 1602 cm-1 during photodegradation. The rates of UV-degradation of hardwood and softwood surfaces were compared and it was found that hardwoods degrade at a faster rate than softwoods. The syringyl structures in hardwood lignin are more sensitive to photochemical degradation than guaiacyl structures. The rate of photodegradation increased with increasing intensity of the irradiated laser energy.


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