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Amino Acids and Vitamin Production
Published in Debabrata Das, Soumya Pandit, Industrial Biotechnology, 2021
Every year 35,000 metric tons of L-lysine is produced. Industrially L-lysine is produced by two different fermentation methods. They are categorized as follows: (a) Indirect fermentation: In this type of fermentation two different types of microorganism are used (dual fermentation). For the initial process of fermentation auxotroph mutant of E. coli is used which produces diaminopimelic acid or DAP (Figure 11.4). In the second phase, Aerobacter aerogenes converts diaminopimelic acid into L-lysine. It has been found that the amount of lysine decarboxylase should be lower in the fermentation process in order to reduce the formation of cadaverine, and thus to increase the level of L-lysine production (Ikeda, 2003).Direct Fermentation: Direct fermentation is a process where L-lysine is produced fermentatively from any substance. For production of L-lysine, this process is used throughout the world. It was discovered that L-lysine is produced from carbohydrates using homoserine or with the use of threonine and added methionine auxotroph of Corynebacterium glutamicum. Observing the homoserine auxotroph of Brevibacterium flavum, a process was reported which was of the same kind. It was recognized later as a sensitive threonine mutant because growth was inhibited due to the excessive amount of threonine and therefore, by the addition of methionine, the inhibition was released (Figure 11.5). The reason for the phenomenon was because of the feedback of the inhibition of the residual known as homoserine dehydrogenase which is via threonine. In other bacteria, homoserine auxotrophs were found to produce L-lysine but their yields were lower than that from the auxotroph of the Coryneform bacteria. There was also the production of fairly large amounts of L-lysine by threonine and leucine auxotrophs which was inferior to homoserine auxotroph. Others were also inferior such as that of the auxotroph of Corynebacterium glutamicum and other bacteria (Ikeda, 2003).
Bioreduction potential of chromate resistant bacteria isolated from chromite mine water of Sukinda, Odisha
Published in Bioremediation Journal, 2023
Sasmita Das, Bikash Chandra Behera, Mathummal Sudarshan, Anindita Chakraborty, Hrudayanath Thatoi
The partial 16S rRNA gene sequences of CWB-2 exhibited close similarity with Lysinibacillus boronitolerens (97.47% similarity) (Figure 3). Besides Cr(VI) reduction, Lysinibacillus is also reported as an excellent insecticidal toxic bio-control agent against mosquitoes (Ahsan and Shimizu 2021; Hernández-Peña et al. 2021). Under hostile conditions, Lysinibacillus can form dormant endo-spore resistant to chemicals, heat, and ultraviolet light and may remain active for a longer period. Previously, they were considered members of the genus Bacillus. However, the taxonomic status of these microorganisms, that is, rRNA group 2 of the genus Bacillus, was changed to the genus Lysinibacillus (Ahsan and Shimizu 2021). Lysinibacillus differs from the genus Bacillus having diagnostic amino acids, lysine, and asparate in their cell wall peptide-glycan layers compared to meso-diaminopimelic acid in the genus Bacillus (Miwa et al. 2009). Several researchers have been reported Lysinibacillus sp. as an excellent agent for Cr(VI) bioremediation. Chen et al. (2021) have reported an efficient Lysinibacillus sp HST-98, which could efficiently grow and detoxify 250 mg/L K2CrO4. Besides Cr(VI) reduction, this strain was also observed resistant to other metals (Cu, Ni, Co, Hg, Cd, and Ag) and metalloid (As).
Diversity of culturable nocardioform actinomycetes from wastewater treatment plants in Spain and their role in the biodegradability of aromatic compounds
Published in Environmental Technology, 2018
Albert Soler, Jorge García-Hernández, Andrés Zornoza, José Luis Alonso
A total of 126 actinomycete strains were isolated and purified from the isolation plates. They were all filamentous, cocci or irregular rods, Gram-positive and catalase-positive bacteria [28]. Mucosal colonies had usually cocci morphologies and rough or dull colonies had usually rod morphologies, occasionally with well-developed branches in right angle. All the strains contained mycolic acid, meso-diaminopimelic acid as cell wall diamino acid and arabinose and galactose as whole-cell organism hydrolysates (wall chemotype IV sensu Lechevalier and Lechevalier [51]) (Figure 1); therefore all the isolates were well defined in the suborder Corynebacterineae.
Carboxymethyl cellulase production optimization from Glutamicibacter arilaitensis strain ALA4 and its application in lignocellulosic waste biomass saccharification
Published in Preparative Biochemistry and Biotechnology, 2018
Chirom Aarti, Ameer Khusro, Paul Agastian
In the current scenario, various groups of microorganisms viz. yeast, bacteria, and fungi from diverse sources have received more attention as resources for cellulase. However, bacteria have gained colossal interest among worldwide researchers as robust producer of cellulase because of their high growth rate, thermal stability, alkali tolerance, and presence of multi enzyme complexes.[8] Over the years, diversified groups of novel bacteria viz. Streptomyces abietis,[9]Ornatilinea apprima,[10]Alicyclobacillus cellulosilyticus,[11] and Caldicellulosiruptor changbaiensis[12] from distinct sources have been classified as cellulase producers. Moreover, the isolation of hyper-cellulase producing bacteria using un/less exploited as well as extensively available inexpensive agro-residual substrates is still progressing in extant. The genus Glutamicibacter belongs to the family Micrococcaceae and it is mainly characterized by the presence of meso-diaminopimelic acid in the cell wall. There are very limited research activities revealing the production of industrially and pharmaceutical associated enzymes from Glutamicibacter arilaitensis. G. arilaitensis has the potentiality to utilize various substrates as sole carbon source. However, there is no study reporting the production of cellulase from G. arilaitensis by utilizing cellulose containing cheap feedstock. Considering this, a significant attempt was undertaken in this context to assess the potentiality of goat dung as consequential inexpensive waste substrate for the ample production of cellulase from the new strain of G. arilaitensis using sequential optimization tools. Furthermore, efforts were made to saccharify different lignocellulosic wastes biomass for fermentable sugar production using partially purified cellulase.