Optogenetic Control of Microbial Consortia Populations for Chemical Production

Unravelling a microbial synergy to boost caproate production via carboxylates chain elongation with ethanol

HKIE Transactions ◽

10.33430/v26n2thie-2018-0041 ◽

2019 ◽

Vol 26 (2) ◽

pp. 63-71

Author(s):

Ling Leng ◽

Ying Wang ◽

Peixian Yang ◽

Takashi Narihiro ◽

Masaru Konishi Nobu ◽

...

Keyword(s):

Fatty Acids ◽

Volatile Fatty Acids ◽

Microbial Consortia ◽

Chain Elongation ◽

Desulfovibrio Vulgaris ◽

Rrna Gene ◽

Selective Enrichment ◽

Microbial Network ◽

Cost Efficient ◽

Rrna Gene Sequencing

Chain elongation of volatile fatty acids for medium chain fatty acids production (e.g. caproate) is an attractive approach to treat wastewater anaerobically and recover resource simultaneously. Undefined microbial consortia can be tailored to achieve chain elongation process with selective enrichment from anaerobic digestion sludge, which has advantages over pure culture approach for cost-efficient application. Whilst the metabolic pathway of the dominant caproate producer, Clostridium kluyveri, has been annotated, the role of other coexisting abundant microbiomes remained unclear. To this end, an ethanol-acetate fermentation inoculated with fresh digestion sludge at optimal conditions was conducted. Also, physiological study, thermodynamics and 16 S rRNA gene sequencing to elucidate the biological process by linking the system performance and dominant microbiomes were integrated. Results revealed a possible synergistic network in which C. kluyveri and three co-dominant species, Desulfovibrio vulgaris, Fusobacterium varium and Acetoanaerobium sticklandii coexisted. D. vulgaris and A. sticklandii (F. varium) were likely to boost the carboxylates chain elongation by stimulating ethanol oxidation and butyrate production through a syntrophic partnership with hydrogen (H2) serving as an electron messenger. This study unveils a synergistic microbial network to boost caproate production in mixed culture carboxylates chain elongation.

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339-LB: Modulation of Insulin and Glucagon Secretion by Optogenetic Control of Delta-Cell Electrical Activity in Pancreatic Islets

Diabetes ◽

10.2337/db19-339-lb ◽

2019 ◽

Vol 68 (Supplement 1) ◽

pp. 339-LB

Author(s):

HAIQIANG DOU ◽

CAROLINE A. MIRANDA ◽

QUAN ZHANG ◽

PATRIK RORSMAN ◽

JOHAN TOLö

Keyword(s):

Electrical Activity ◽

Pancreatic Islets ◽

Glucagon Secretion ◽

Insulin And Glucagon Secretion ◽

Delta Cell ◽

Optogenetic Control

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Process Description of an Unconventional Biofilm Formation by Bacterial Cells Autoagglutinating Through Sticky, Long, and Peritrichate Nanofibers

10.26434/chemrxiv.10001924.v1 ◽

2019 ◽

Author(s):

Yoshihide Furuichi ◽

Shogo Yoshimoto ◽

Tomohiro Inaba ◽

Nobuhiko Nomura ◽

Katsutoshi Hori

Keyword(s):

Formation Process ◽

Biofilm Formation ◽

Extracellular Polymeric Substances ◽

Waste Treatment ◽

Large Cell ◽

Dlvo Theory ◽

Bacterial Cells ◽

Chemical Production ◽

Discontinuous Surface ◽

Cell Cell

Biofilms are used in environmental biotechnologies including waste treatment and environmentally friendly chemical production. Understanding the mechanisms of biofilm formation is essential to control microbial behavior and improve environmental biotechnologies. Acinetobacter sp. Tol 5 autoagglutinate through the interaction of the long, peritrichate nanofiber protein AtaA, a trimeric autotransporter adhesin. Using AtaA, without cell growth or the production of extracellular polymeric substances, Tol 5 cells quickly form an unconventional biofilm. In this study, we investigated the formation process of this unconventional biofilm, which started with cell–cell interactions, proceeded to cell clumping, and led to the formation of large cell aggregates. The cell–cell interaction was described by DLVO theory based on a new concept, which considers two independent interactions between two cell bodies and between two AtaA fiber tips forming a virtual discontinuous surface. If cell bodies cannot collide owing to an energy barrier at low ionic strengths but approach within the interactive distance of AtaA fibers, cells can agglutinate through their contact. Cell clumping proceeds following the cluster–cluster aggregation model, and an unconventional biofilm containing void spaces and a fractal nature develops. Understanding its formation process would extend the utilization of various types of biofilms, enhancing environmental biotechnologies.

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RHEOLOGICAL PROPERTIES OF CERAMIC MASSES: IMPROVEMENT BY COMPLEX MATERIAL ACTIVATION

The Russian Automobile and Highway Industry Journal ◽

10.26518/2071-7296-2019-3-334-351 ◽

2019 ◽

Vol 16 (3) ◽

pp. 334-351

Author(s):

A. S. Mavlyanov ◽

E. K. Sardarbekova

Keyword(s):

Rheological Properties ◽

Raw Materials ◽

Sensitivity Coefficient ◽

Raw Material ◽

Clay Material ◽

Fibrous Materials ◽

Chemical Production ◽

Production Wastes ◽

Pass Through ◽

The Masses

Introduction. The objective of the research is to study the effect of the complex activation of the alumina raw material on the rheological properties of the ceramic mass. In addition, the authors investigate solutions for the application of optimal coagulation structures based on loams and ash together with plastic certificates.Materials and methods. The authors used the local forest like reserves of clay loams at the BashKarasu, ash fields of the Bishkek Central Heating Centre (BTEC) and plasticizer (sodium naphthenate obtained from alkaline chemical production wastes) as fibrous materials. Moreover, the authors defined technological properties of raw materials within standard laboratory methodology in accordance with current GOSTs.Results. The researchers tested plastic durability on variously prepared masses for the choice of optimal structures. The paper demonstrated the plastic durability of complexly activated compounds comparing with non-activated and mechanically activated compounds. The sensitivity coefficient increased the amount of clay loams by mechanically and complexly activated, which predetermined the possibility of intensifying the process of drying samples based on complexly activated masses.Discussion and conclusions. However, mechanical activation of clay material reduces the period of relaxation and increases the elasticity coefficient of ceramic masses by 1.8–3.4 times, meanwhile decreases elasticity, viscosity and the conventional power during molding, which generally worsens the molding properties of the masses. Сomplex activation of ash-clay material decreases the period of relaxation and provides an increase in elasticity, plasticity of ceramic masses by 46–47%, reduction in viscosity by 1.5–2 times, conventional power on molding by 37–122% in comparison with MA clay loams. Ceramic masses based on spacecraft alumina raw materials belong to the SMT with improved rheological properties; products based on them pass through the mouthpiece for 5–7 seconds.

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