scholarly journals Klebsiella Pneumoniae Metabolic Regulation and its Application in 1,3-Propanediol Production

2021 ◽  
Author(s):  
Yadong Wang ◽  
Jing Mu ◽  
Yonghong Liao ◽  
Yuxuan Wang ◽  
Xian Yin ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Klebsiella Pneumoniae ◽  
Conversion Rate ◽  
Parent Strain ◽  
Recombinant Strain ◽  
Metabolic Regulation ◽  
Pathway Engineering ◽  
Glycerol Metabolism ◽  
Knock Out ◽  
By Products

Abstract Klebsiella pneumoniae is a well-known model organism for glycerol metabolism to produce 1,3-propanediol (1,3-PD), a valuable chemical intermediate for materials, such as polyesters. However, the relatively low conversion rate and productivity, as well as the accumulation of by-products such as lactic acid, ethanol and acetic acid, inhibit the production of 1,3-PD. Hereby, the 1,3-PD metabolism in K. pneumoniae was regulated through pathway engineering by using CRISPR-Cas9 technology for the first time to knock out the ldhA gene of lactate dehydrogenase,the adhE gene of alcohol dehydrogenase and the ack gene of acetate kinase respectively as needed and constructed recombinant bacteria ldhA(−), ldhA(−)-ack(−), ldhA(−)-adhE(−) and ldhA(−)-adhE(−)-ack(−), all of which showed a decrease in by-product production, leading to a higher NADH availability, and 1,3-BD production was significantly increased. In the shake flask fermentation, the 1,3-PD yield and conversion rate of the recombinant strain ldhA(−), ldhA(−)-ack(−), ldhA(−)-adhE(−), ldhA(−)-adhE(−)-ack(−) were higher than those of the parent strain. In the fed-batch fermentation, the 1,3-PD yield and conversion rate of the recombinant strain ldhA(−) were higher than those of the parent strain. The biomass of the recombinant strain ldhA(−)-adhE(−)-ack(−) was reduced due to the accumulation of acetic acid, but its 1,3-PD conversion rate was still higher than that of the parent strain. The higher productivity and fewer by-products concluded that the four Klebsiella pneumoniae recombinant strains could be promising industrial strain for economical production of 1,3-PD.

Performance of the house cricket (Acheta domesticus) on by-product diets in small-scale production

2021 ◽  
pp. 1-6
Author(s):  
J.M. Sorjonen ◽  
M. Karhapää ◽  
S. Holm ◽  
A. Valtonen ◽  
H. Roininen
Keyword(s):  
Conversion Rate ◽  
Development Time ◽  
Acheta Domesticus ◽  
Small Scale ◽  
Scale Production ◽  
Feed Conversion ◽  
House Cricket ◽  
Current Production ◽  
Feed Conversion Rate ◽  
By Products

As insect farming is becoming more popular in Europe and in the US, the use of food industry by-products in insects’ feed is drawing more attention. However, it is still unclear how to maximise the use of by-products in the feeds while meeting the nutritional requirements and maintaining profitable rearing yields with the current production technology. In this study, we conducted an experiment in Finnish small-scale cricket farming and laboratory conditions to determine whether five diet treatments, including by-product diets with barley mash and turnip rape, modify the overall fresh yield (kg), development time and feed conversion rate of the house crickets (Acheta domesticus). We discovered that the diets differed in the overall fresh cricket yield (kg) but not in the development time or the feed conversion rate of the crickets. The diets with a high proportion of by-product decreased the price of the feed but at the same time reduced the yield. Based on our results, complex by-product diets with the by-product proportion of 20-41% are the most suitable for house cricket rearing.

A SYNTHESIS OF α-NAPHTHYL-ACETIC ACID AND SOME HOMOLOGUES

1939 ◽  
Vol 17b (1) ◽  
pp. 14-20 ◽  
Author(s):  
Richard H. F. Manske ◽  
Archie E. Ledingham
Keyword(s):  
Acetic Acid ◽  
Methyl Ether ◽  
Valeric Acid ◽  
Diacetic Acid ◽  
Standard Procedures ◽  
Crude Product ◽  
By Products

In the course of a study of the synthesis of α-naphthyl-acetic acid, a method was elaborated by Dr. A. Cambron that made available large quantities of α-chloromethyl-naphthalene. During the purification of the crude product and in the later stages of the synthesis we have encountered a number of by-products. Among others, these include methyl α-naphthyl-methyl ether, di-α-naphthyl-methyl ether, α-naphthyl carbinol, and 1:5-bis-chloromethyl-naphthalene. The last-named was converted into 1:5-naphthylene-diacetic acid, m.p. 280 °C., via the corresponding nitrile. δ-(1-Naphthyl)-valeric acid, m.p. 84 °C., and ε-(1-naphthyl)-hexoic acid, m.p. 62 °C., were synthesized by standard procedures.

Proteome and metabolome profiling of wild-type and YCA1 -knock-out yeast cells during acetic acid-induced programmed cell death

2015 ◽  
Vol 128 ◽  
pp. 173-188 ◽  
Author(s):  
Valentina Longo ◽  
Maša Ždralević ◽  
Nicoletta Guaragnella ◽  
Sergio Giannattasio ◽  
Lello Zolla ◽  
...  
Keyword(s):  
Cell Death ◽  
Acetic Acid ◽  
Programmed Cell Death ◽  
Yeast Cells ◽  
Wild Type ◽  
Knock Out ◽  
Metabolome Profiling

scholarly journals On the asymptotic stability of advection-diffusion equations of mass transport in a bubble column bioreactor

2021 ◽  
Vol 2090 (1) ◽  
pp. 012035
Author(s):  
Paola Lecca ◽  
Angela Re
Keyword(s):  
Acetic Acid ◽  
Control System ◽  
Asymptotic Stability ◽  
Bubble Column ◽  
Bubble Column Reactor ◽  
Dissolved Gas ◽  
Advection Diffusion Equation ◽  
Bubble Column Bioreactor ◽  
Advection Diffusion ◽  
By Products

Abstract This study presents an asymptotic stability analysis of a model of a bioreactor converting carbon monoxide (CO) gas into ethanol through a C. autoethanogenum biocatalyst. The configuration is a bubble column reactor with co-current gas-liquid flows where gas feed is introduced by a gas distributor placed at the bottom of the column. A pure culture of C. autoethanogenum is subsequently injected at the bottom of the column; therein, cells are dispersed in the liquid and consume the dissolved gas and release by-products such as ethanol and acetic acid. Cellular growth and byproduct secretion are affected by spatially varying dissolved gas concentrations due to advection-diffusion mass transports which are induced by the effect of the injection pressure and gravitational force. The model accounts for four species representing the biomass, the CO substrate in the liquid phase, and two by-products - ethanol and acetic acid. Substrate dynamics is described by an advection-diffusion equation. We investigate the asymptotic stability of the biomass dynamics that is a requirement for the system’s controllability, i.e. for the possibility to steer a dynamical system from an arbitrary initial state to an arbitrary final state using a set of controls. The concept of stability of the controls is extremely relevant to controllability since almost every workable control system is designed to be stable. If a control system is not stable, it is usually of no use in practice in industrial processes. In the case of a bioreactor, the control is the biomass and controllability is the possibility of modulating through this control the ethanol production. We present a test for asymptotic stability, based on the analysis of the properties of the dynamic function defining its role as storage function.

scholarly journals Effect of Ammonia and Indole-3-acetic Acid Producing Endophytic Klebsiella pneumoniae YNA12 as a Bio-Herbicide for Weed Inhibition: Special Reference with Evening Primroses

Plants ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 761
Author(s):  
Sang-Mo Kang ◽  
Saqib Bilal ◽  
Raheem Shahzad ◽  
Yu-Na Kim ◽  
Chang-Wook Park ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Klebsiella Pneumoniae ◽  
Culture Filtrate ◽  
Catalase Activity ◽  
Endophytic Bacteria ◽  
Germination Rate ◽  
Herbicidal Activity ◽  
Dependent Manner ◽  
Evening Primrose ◽  
Indole 3 Acetic Acid

Information on the use of endophytic bacteria as a bio-herbicide for the management of weed control in agricultural fields is limited. The current study aimed to isolate endophytic bacteria from evening primroses and to screen them for their bio-herbicidal activity. Two isolated endophytic bacteria (Pantoea dispersa YNA11 and Klebsiella pneumoniae YNA12) were initially screened for citrate utilization and for indole-3-acetic acid (IAA) and catalase production. The preliminary biochemical assessment showed YNA12 as a positive strain. Ammonia, catalase, and IAA in its culture filtrate were quantified. Gas Chromatography/Mass Spectroscopy- Selective Ion Monitoring (GC/MS-SIM) analysis revealed the production of IAA by YNA12 in a time-dependent manner. YNA12 also exhibited significant ammonia-producing potential and catalase activity against hydrogen peroxide. The YNA12 culture filtrate significantly inhibited the germination rate of evening primrose seeds, resulting in a marked reduction in seedling length and biomass compared with those of the control seeds. Moreover, the culture filtrate of YNA12 significantly accelerated the endogenous abscisic acid (ABA) production and catalase activity of evening primrose seedlings. Macronutrient regulation was adversely affected in the seedlings exposed to the culture filtrate of YNA12, leading to inhibition of seed germination. The current results suggest that endophytic YNA12 may be used as a potent bio-herbicidal agent for controlling weed growth and development.

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