scholarly journals Bacterial inducible expression of plant cell wall-binding protein YesO through conflict between Glycine max and saprophytic Bacillus subtilis

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Haruka Sugiura ◽  
Ayumi Nagase ◽  
Sayoko Oiki ◽  
Bunzo Mikami ◽  
Daisuke Watanabe ◽  
...  

Abstract Saprophytic bacteria and plants compete for limited nutrient sources. Bacillus subtilis grows well on steamed soybeans Glycine max to produce the fermented food, natto. Here we focus on bacterial responses in conflict between B. subtilis and G. max. B. subtilis cells maintained high growth rates specifically on non-germinating, dead soybean seeds. On the other hand, viable soybean seeds with germinating capability attenuated the initial growth of B. subtilis. Thus, B. subtilis cells may trigger saprophytic growth in response to the physiological status of G. max. Scanning electron microscope observation indicated that B. subtilis cells on steamed soybeans undergo morphological changes to form apertures, demonstrating cell remodeling during saprophytic growth. Further, transcriptomic analysis of B. subtilis revealed upregulation of the gene cluster, yesOPQR, in colonies growing on steamed soybeans. Recombinant YesO protein, a putative, solute-binding protein for the ATP-binding cassette transporter system, exhibited an affinity for pectin-derived oligosaccharide from plant cell wall. The crystal structure of YesO, in complex with the pectin oligosaccharide, was determined at 1.58 Å resolution. This study expands our knowledge of defensive and offensive strategies in interspecies competition, which may be promising targets for crop protection and fermented food production.

2001 ◽  
Vol 276 (46) ◽  
pp. 43010-43017 ◽  
Author(s):  
Alexander C. J. Freelove ◽  
David N. Bolam ◽  
Peter White ◽  
Geoffrey P. Hazlewood ◽  
Harry J. Gilbert

2007 ◽  
Vol 73 (12) ◽  
pp. 3803-3813 ◽  
Author(s):  
Akihito Ochiai ◽  
Takafumi Itoh ◽  
Akiko Kawamata ◽  
Wataru Hashimoto ◽  
Kousaku Murata

ABSTRACT Plant cell wall degradation is a premier event when Bacillus subtilis, a typical saprophytic bacterium, invades plants. Here we show the degradation system of rhamnogalacturonan type I (RG-I), a component of pectin from the plant cell wall, in B. subtilis strain 168. Strain 168 cells showed a significant growth on plant cell wall polysaccharides such as pectin, polygalacturonan, and RG-I as a carbon source. DNA microarray analysis indicated that three gene clusters (yesOPQRSTUVWXYZ, ytePQRST, and ybcMOPST-ybdABDE) are inducibly expressed in strain 168 cells grown on RG-I. Cells of an industrially important bacterium, B. subtilis strain natto, fermenting soybeans also express the gene cluster including the yes series during the assimilation of soybean used as a carbon source. Among proteins encoded in the yes cluster, YesW and YesX were found to be novel types of RG lyases releasing disaccharide from RG-I. Genetic and enzymatic properties of YesW and YesX suggest that strain 168 cells secrete YesW, which catalyzes the initial cleavage of the RG-I main chain, and the resultant oligosaccharides are converted to disaccharides through the extracellular exotype YesX reaction. The disaccharide is finally degraded into its constituent monosaccharides through the reaction of intracellular unsaturated galacturonyl hydrolases YesR and YteR. This enzymatic route for RG-I degradation in strain 168 differs significantly from that in plant-pathogenic fungus Aspergillus aculeatus. This is, to our knowledge, the first report on the bacterial system for complete RG-I main chain degradation.


Author(s):  
Venkatasubramanian Sivakumar

Background: In the growing environmental concern use of natural products, efficient processes and devices are necessary. Solid-Liquid extraction of active Ingredients from Plant materials is one of the important unit operations in Chemical Engineering and need to be enhanced. Objectives: Since, these active ingredients are firmly bound to the plant cell wall membrane, which pose mass-transfer resistance and need to get detached through the use of suitable process intensification tools such as ultrasound and suitable devices. Therefore, detailed analysis and review is essential on development made in this area through Publications and Patents. Hence, the present paper illustrates the development of ultrasound assisted device for solid-liquid extraction are presented in this paper. Methods: Advantages such as % Yield, Reduction in extraction time, use of ambient conditions, better process control, avoidance or minimizing multi stage extraction could be achieved due to the use of ultrasound in extraction as compared to conventional processes. Conclusions: Use of ultrasound to provide significant improvements in the extraction of Vegetable tannins, Natural dyes for application in Leather processing has been demonstrated and reported earlier. These enhancement could be possible through various effects of ultrasound such as better flow of solvents through micro-jet formation, mass transfer enhancement due to rupture of plant cell wall membranes through acoustic cavitation, better leaching due to micro-mixing and acoustic streaming effects. This approach would minimize material wastage; thereby, leading to eco-conservation of plant materials, which is very much essential for better environment. Hence, various methods and design for application of ultrasound assisted solid-liquid extractor device are necessary.


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