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BILDUNG VON CELLULASE UND PROTEIN BEIM WACHSTUM VON CHAETOMIUM CELLULOLYTICUM AUF CELLULOSEHALTIGEN SUBSTRATEN
No full textMicrobial protein (SCP) production from ligno-cellulosic materials and
also the enzymatic hydrolysis of cellulose and hemicellulose have received
increased interest in recent years. The thermotolerant fungus
Chaetomium cellulolyticum /1/ was recently reported as an object for
SCP production from cellulosic substrates /2,3/. In the present paper
we examined growth of C. cellulolyticum on glucose, crystalline cellulose,
and on chemically non-treated newspaper. Studies were also made
on SCP production and on formation of extracellular cellulase. A mutant
strain of C, cellulolyticum was isclated which produced higher levels |
of extracellular cellulase compared to the parent type. In order to
study the effect of chemical pretreatment of ligno-cellulosic substrate
on SCP production, the mutant was grown on alkali-treated newspaper
Herrn Prof. Dr. 0. Kandler, Universität München, zum 60. Geburtstag gewidmet
No full textAir may be used as the fluid continuous phase for the aerobic fermentation of
concentrated solutions of sugar with Saccharomyces cerevisiae in a fluidized bed
to fulfill the following functions
- fluidization of the yeast particles
- supply of oxygen to the yeast
- cooling the particles by evaporation of water
- formation of particles by granulation (by spraying the culture medium on the
fluidized bed)
- mixing the particles
OPTIMIERUNG DES AMINOSÄUREZUSATZES ZU SCP (METHYLOMONAS CLARA) FÜR DIE AUFZUCHT JAPANISCHER WACHTELN (COT.COT.JAPONICA)
No full textOptimizing the amino acid supplementation of SCP (methylomonas clara)
in raising Japanese baby quail (cot.cot.japonica) |
Several experiments with a bacterial Single Cell Protein (methylomonas
clara) as the sole source of protein were conducted on day old Japanese
quail using semipurified diets (corn starch, soy oil, minerals, vitamins).
A mixture of soy flour and isolated soy protein (Purina RP 100)
supplemented with dl-methionine and glycine served as control protein.
All diets were calculated isocalorically and were fed as pellets. The
trials were finished after 16 - 18 days.
In experiments with 25% SCP methionine could be identified as the first
limiting amino acid in SCP and arginine as the second one. Best results
were obtained with a total of 4.9 sulphur amino acids and 6.1 arginine
calculated as percentage of SCP amino acid protein. With 25-303 dietary
SCP supplemented with methionine and arginine at the above level, growth
was only slightly (2-5%) below the control level. However 50% dietary
SCP resulted in growth rates of only 85 - 88% of the soy control.
Inconsistent results were obtained by addition of glutamic acid to SCP
diets
Microbial chassis engineering drives heterologous production of complex secondary metabolites
No full textThe cryptic secondary metabolite biosynthetic gene clusters (BGCs) far outnumber currently known secondary metabolites. Heterologous production of secondary metabolite BGCs in suitable chassis facilitates yield improvement and discovery of new-to-nature compounds. The two juxtaposed conventional model microorganisms, Escherichia coli, Saccharomyces cerevisiae, have been harnessed as microbial chassis to produce a bounty of secondary metabolites with the help of certain host engineering. In last decade, engineering non-model microbes to efficiently biosynthesize secondary metabolites has received increasing attention due to their peculiar advantages in metabolic networks and/or biosynthesis. The state-of-the-art synthetic biology tools lead the way in operating genetic manipulation in non-model microorganisms for phenotypic optimization or yields improvement of desired secondary metabolites. In this review, we firstly discuss the pros and cons of several model and non-model microbial chassis, as well as the importance of developing broader non-model microorganisms as alternative programmable heterologous hosts to satisfy the desperate needs of biosynthesis study and industrial production. Then we highlight the lately advances in the synthetic biology tools and engineering strategies for optimization of non-model microbial chassis, in particular, the successful applications for efficient heterologous production of multifarious complex secondary metabolites, e.g., polyketides, nonribosomal peptides, as well as ribosomally synthesized and post-translationally modified peptides. Lastly, emphasis is on the perspectives of chassis cells development to access the ideal cell factory in the artificial intelligence-driven genome era. © 2022 Elsevier Inc.National Natural Science Foundation of China; Natural Science Foundation of Shandong Province; National Key Research and Development Program of China:
This work was supported by the National Key R&D Program of China (Grant nos. 2021YFC2100500 , 2019YFA0905700 ), National Natural Science Foundation of China (Grant nos. 32070060 , 32161133013 ), Shandong Provincial Natural Science Foundation (Grant no. ZR2019JQ11 , ZR2019ZD18 )
Global RNA interactome of Salmonella discovers a 5' UTR sponge for the MicF small RNA that connects membrane permeability to transport capacity.
No full textThe envelope of Gram-negative bacteria is a vital barrier that must balance protection and nutrient uptake. Small RNAs are crucial regulators of the envelope composition and function. Here, using RIL-seq to capture the Hfq-mediated RNA-RNA interactome in Salmonella enterica, we discover envelope-related riboregulators, including OppX. We show that OppX acts as an RNA sponge of MicF sRNA, a prototypical porin repressor. OppX originates from the 5' UTR of oppABCDF, encoding the major inner-membrane oligopeptide transporter, and sequesters MicF's seed region to derepress the synthesis of the porin OmpF. Intriguingly, OppX operates as a true sponge, storing MicF in an inactive complex without affecting its levels or stability. Conservation of the opp-OppX-MicF-ompF axis in related bacteria suggests that it serves an important mechanism, adjusting envelope porosity to specific transport capacity. These data also highlight the resource value of this Salmonella RNA interactome, which will aid in unraveling RNA-centric regulation in enteric pathogens
Novel 2,4-disubstituted quinazoline analogs as antibacterial agents with improved cytotoxicity profile: Modification of the benzenoid part.
No full textBacterial resistance to currently used antibiotics demands the development of novel antibacterial agents with good safety margins and sufficient efficacy against multi-drug resistant isolates. We have previously described the synthesis of N-butyl-2-(butylthio)quinazolin-4-amine (I) as an optimized hit with broad-spectrum antibacterial activity and low cytotoxicity. In addition, we have identified a potential growing vector for this series of compounds. Herein, we describe further hit optimization which includes systematic diversifications of both the benzenoid part and the substituents at position 6 and 7 of compound I. Growing of the molecule beside the core modifications yielded several compounds with remarkable anti(myco)bacterial activity against a panel of pathogenic bacteria, including drug-resistant strains. Compound 12 showed a 2-4 fold improvement in activity than I against S. aureus Newman, S. pneumoniae DSM-20566 and E. faecalis DSM-20478. The compounds also showed a good safety profile towards human HepG2 cells
Description of the novel planctomycetal genus Bremerella, containing Bremerella volcania sp. nov., isolated from an active volcanic site, and reclassification of Blastopirellula cremea as Bremerella cremea comb. nov.
No full textPlanctomycetes are part of the PVC superphylum together with Verrucomicrobia, Chlamydiae and others. They are budding bacteria with very distinctive characteristics, such as a remarkable morphology and cell biology. Planctomycetes can be found in almost all habitats, and seem to have a preference for marine biotic and abiotic surfaces, on which they frequently occur in biofilm-forming communities. To extend the number of axenic cultures of planctomycetal strains, we isolated Pan97T from a biofilm in a volcanic site close to the Italian island Panarea in the Thyrrhenian Sea. The physiology, genome and morphology of the novel strain were characterised revealing typical planctomycetal characteristics, such as, division by polar budding and presence of crateriform structures. The strain shows pear-shaped cells of 1.5 ± 0.3 µm × 0.8 ± 0.2 µm and forms white- to cream-coloured colonies on solid medium. Strain Pan97T is mesophilic and neutrophilic, since growth was observed at a pH range of 5.5-9.5 with optimal growth at pH 7.0 and at a temperature range of 15-40 °C with a maximal growth rate at 36 °C. Pan97T has a genome size of 6,496,182 bp with a G + C content of 56.2%. 5264 protein-coding genes were identified, of which 2141 genes (41%) encode hypothetical proteins. Based on the phylogenetic analysis, we suggest that Pan97T (DSM 101992T = LMG 29460T) represents a novel species of a novel genus within the family Planctomycetaceae, for which we propose the name Bremerella gen. nov., with strain Pan97T classified as Bremerella volcania sp. nov. Based on our analysis, we also propose the reclassification of Blastopirellula cremea Lee et al. 2013 as Bremerella cremea comb. nov., as this species is considered to be the type species of the novel genus Bremerella
Three marine strains constitute the novel genus and species Crateriforma conspicua in the phylum Planctomycetes.
No full textPlanctomycetes is a ubiquitous phylum of mostly aquatic bacteria that have a complex lifestyle and an unusual cell biology. Here, we describe three strains of the same novel genus and species isolated from three different environments; from a red biofilm at a hydrothermal vent in the Mediterranean Sea, from sediment in a salt-water fish tank, and from the surface of algae at the coast of the Balearic island Mallorca. The three strains Mal65T (DSM 100706T = LMG 29792T, Pan14r (DSM 29351 = LMG 29012), and V7 (DSM 29812 = CECT 9853 = VKM B-3427) show typical characteristics of the Planctomycetaceae family, such as cell division by budding, crateriform structures and growth in aggregates or rosettes. The strains are mesophilic, neutrophilic to alkaliphilic as well as chemoheterotrophic and exhibit doubling times between 12 and 35 h. Based on our phylogenetic analysis, the three strains represent a single novel species of a new genus, for which we propose the name Crateriforma conspicua gen. nov. sp. nov
