scholarly journals Early and Late Trisporoids Differentially Regulate β-Carotene Production and Gene Transcript Levels in the Mucoralean Fungi Blakeslea trispora and Mucor mucedo

2013 ◽  
Vol 79 (23) ◽  
pp. 7466-7475 ◽  
Author(s):  
Yamuna Sahadevan ◽  
Mareike Richter-Fecken ◽  
Kerstin Kaerger ◽  
Kerstin Voigt ◽  
Wilhelm Boland
Keyword(s):  
Life Cycles ◽  
Regulatory Function ◽  
Blakeslea Trispora ◽  
Gene Transcript ◽  
Carotenoid Cleavage Dioxygenase ◽  
Developmental Phase ◽  
Acid Biosynthesis ◽  
Content Type ◽  
Mucor Mucedo ◽  
Β Carotene

ABSTRACTThe multistep cleavage of carotenoids inMucoralesduring the sexual phase results in a cocktail of trisporic acid (C18) sex pheromones. We hypothesized that the C18trisporoid intermediates have a specific regulatory function for sex pheromone production and carotenogenesis that varies with genus/species and vegetative and sexual phases of their life cycles. Real-time quantitative PCR kinetics determined forBlakeslea trisporadisplayed a very high transcript turnover in the gene for carotenoid cleavage dioxygenase,tsp3, during the sexual phase. Anin vivoenzyme assay and chromatographic analysis led to the identification of β-apo-12′-carotenal as the first apocarotenoid involved in trisporic acid biosynthesis inB. trispora. Supplementation of C18trisporoids, namely D'orenone, methyl trisporate C, and trisporin C, increasedtsp3transcripts in the plus compared to minus partners. Interestingly, thetsp1gene, which is involved in trisporic acid biosynthesis, was downregulated compared totsp3irrespective of asexual or sexual phase. Only the minus partners of bothB. trisporaandMucor mucedohad enhanced β-carotene production after treatment with C20apocarotenoids, 15 different trisporoids, and their analogues. We conclude that the apocarotenoids and trisporoids influence gene transcription and metabolite production, depending upon the fungal strain, corresponding genus, and developmental phase, representing a “chemical dialect” during sexual communication.

Medium optimization and downstream process design for the augmented yield of β-Carotene using fungi Blakeslea trispora

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Umesh Luthra ◽  
Prabhakar Babu ◽  
Remya R.R. ◽  
Angeline Julius ◽  
Yogesh Patel ◽  
...  
Keyword(s):  
Process Design ◽  
Medium Optimization ◽  
Corn Starch ◽  
Uv Spectroscopy ◽  
Maximum Activity ◽  
Blakeslea Trispora ◽  
Content Type ◽  
Natural Oils ◽  
Lower Temperature ◽  
Β Carotene

Purpose β-Carotene is the most appropriate and significant precursor of vitamin A. Synthetic carotene supplements have been known to pose a threat to human health, making natural sources such as the indefensible choice for the production and extraction of carotene. Design/methodology/approach This study considers Blakeslea trispora, a filamentous fungus, as a source of production of carotenoids by fermentation and wet and dry mycelium were used to analyse and obtain better extraction results. Findings In this study, natural oils such as soy oil and cottonseed oil were incorporated into fermentation media to increase the production of carotene. For the optimization process, Plackett–Burman and one-factor-at-a-time (OVAT) models were identified as being of great value. Originality/value OVAT was carried out for corn starch because it plays a major role in the production of carotene and the corn starch at 30 g/L concentration has shown the maximum activity of 3.48 mg/gm. After optimizing process variables, submerged fermentation was eventually carried out under highly controlled media conditions. The resulting product was quantified using UV spectroscopy and extraction of carotene has been observed in the presence of various solvents. Among a range of solvents used, the methylene Di chloride produced-carotene at 86% recovery at a significantly lower temperature of 35°C.

Optimizing β-carotene production by Blakeslea trispora using bug damaged wheat

2018 ◽  
Vol 47 (3) ◽  
pp. 189-195
Author(s):  
Serap Durakli Velioglu ◽  
Goksel Tirpanci Sivri
Keyword(s):  
Response Surface Methodology ◽  
Industrial Waste ◽  
Design Methodology ◽  
Model Fit ◽  
Quadratic Model ◽  
Blakeslea Trispora ◽  
Natural Food ◽  
Control Medium ◽  
Content Type ◽  
Β Carotene

Purpose β-carotene, found naturally in many foods, has been widely used as a colourant in various products. The aim of this study is to optimize the production of β-carotene by Blakeslea trispora using bug-damaged wheat as the main nitrogen and carbon source. Design/methodology/approach Response surface methodology (RSM) has been used to determine the optimum concentrations of media components for the maximum β-carotene production. β-carotene concentration was determined quantitively using a spectrophotometric method. Findings A full quadratic model fit the data best for β-carotene production with a high R2 value (0.999). Using optimized media increased the production of β-carotene by B. trispora DSM-2387 and B. trispora DSM-2388 to a higher level (250.407 mg/l) than the control medium (72.195 mg/l). Originality/value This study showed that bug-damaged wheat, an agro-industrial waste having low economical value, may be used as a valuable substrate for microbial production of β-carotene, a natural food colourant possessing high economical value.

Corporate governance practices and firm performance: a configurational analysis across corporate life cycles

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Hala M. Amin ◽  
Ehab K.A. Mohamed ◽  
Mostaq M. Hussain
Keyword(s):  
Corporate Governance ◽  
Firm Performance ◽  
Analytical Approach ◽  
Research Study ◽  
Performance Outcomes ◽  
Life Cycles ◽  
Related Activity ◽  
Content Type ◽  
And Performance ◽  
Country Specific

Purpose This study aims to explore corporate governance (CG) practices that can lead to firms’ better performance in different organizational life cycles. The authors propose a configurational approach to explore how a set of CG practices combine in bundles to achieve high performance outcomes for firms across their corporate life cycles. Design/methodology/approach Fuzzy-set qualitative comparative analysis was used to analyze a sample of data of 21 countries and 9 industries. Data referred to the period of 9 years extending from the year 2005 to the year 2013. Findings This study reveals that there are multiple CG practices that exist through firms that can achieve high firm performance. Moreover, CG practices combine in different ways for firms in their growth, maturity and declining stages. Research limitations/implications This study demonstrates the value of using a configurational analytical approach to explore both the firm and country-specific CG practices (together) that engage firms to achieve the desired level of performance across the corporate life cycles. Practical implications The current study draws attention to the policymakers’ need to assess the current level of regulatory and competitive development of their countries and form policy accordingly. The approach used in the current research study not only offers the linkages between CG and performance to managers as incentives to comply with regulation but also to view CG-related activity as a strategic move. Social implications The approach used in the current research study not only offers the linkages between CG and performance to managers as incentives to comply with regulation but also to view CG-related activity as a strategic move. Originality/value This study broadening the focus of CG studies to include a rigorous explanation of the global CG phenomena and to provide effective solutions for the practitioners. Contribution to Impact This study demonstrates the value of using a configurational analytical approach to explore both the firm and country-specific CG practices (together) that engage firms to achieve the desired level of performance across the corporate life cycles.

Financial flexibility, managerial efficiency and firm life cycle on firm performance

2019 ◽  
Vol 16 (2) ◽  
pp. 168-180
Author(s):  
Heng-Yu Chang ◽  
Chun-Ai Ma
Keyword(s):  
Life Cycle ◽  
Firm Performance ◽  
Stock Market ◽  
Life Cycles ◽  
Mature Stage ◽  
Chinese Stock Market ◽  
Financial Flexibility ◽  
Content Type ◽  
Listed Firms ◽  
Managerial Efficiency

Purpose As the capital market in China is still developing, several constraints on a Chinese-listed firm’s financing strategy have a direct impact on its financial flexibility. The purpose of this paper is to reconstruct traditional financial flexibility index (FFI) derived from the western context, provide empirical evidence within eastern context by modified FFI and examine how the managerial efficiency of Chinese-listed firms is demonstrated with modified FFI to escort corporate life cycle hypothesis. Design/methodology/approach By tailored FFI to fit the contemporary operations of Chinese-listed firms, this study investigates how managerial efficiency varies across different life stages to demonstrate the moderating power in the firm performance of financially flexible firm. Findings It is found that financially flexible firms in the Chinese stock market generally experience good firm performance, yet the managerial efficiency could gradually be diminishing at their mature stage even firms’ financial flexibility remains consistent with the agency theory. This paper sheds light on the necessity to reexamine the components in financial flexibility based on the eastern context, and provides avenue to further understand the managerial behavior of Chinese listed firms when considering firm life cycles. Research limitations/implications Although it is difficult for this current study to offer the precise weights on each factor in calculating financial flexibility, the judgment matrix method is adopted to at least provide reliable estimates in accordance with Chinese business contexts with less than 10 percent errors in contrast to the actual weights. Practical implications This modified FFI is particularly suitable for Chinese-listed firms under certain unique financial reporting regulations by adjusting a number of weights and factors. This study may help practitioners understand the managerial conduct of publicly listed firms in China. Originality/value The paper constructs a modified FFI with Chinese stock market characteristics embedded, and provides insightful evidence to explain the new pecking order theory by considering the life cycle stage of Chinese-listed companies.

A cradle-to-cradle analysis in the toner cartridge supply chain using fuzzy recycling production approach

2019 ◽  
Vol 30 (2) ◽  
pp. 329-345 ◽  
Author(s):  
Chun-Wei Lin ◽  
Shiou-Yun Jeng ◽  
Ming-Lang Tseng ◽  
Raymond Tan
Keyword(s):  
Evaluation System ◽  
Design Method ◽  
Environmental Law ◽  
Integrated Approach ◽  
Life Cycles ◽  
Green Product ◽  
Production Plan ◽  
Content Type ◽  
The Usa ◽  
Cradle To Cradle

Purpose The purpose of this paper is to develop an integrated approach for a green product cradle-to-cradle (C2C) fuzzy recycling production planning model. Design/methodology/approach This paper applies the failure mode and effects analysis technique and Taguchi experimental design method, develops a green product C2C performance evaluation system that considers the fuzzy impacts of environmental laws and regulations, green goodwill, and environmental efficiency of targeting countries, and decides both the optimal green production plan and estimated optimal life cycles. Findings This study compares the different degree of maturity in environmental regulations, and various recycling situations are simulated to demonstrate the successful applicability of the proposed model as well as the incentive policy for Taiwan, the USA and Bangladesh. Originality/value Previous studies failed both to develop a holistic recycling production plan which is able to consider both the optimal combination of recycled components used and final green products produced with the maximum total resultant sales profit and to consider the potential failure phenomenon of recycled components adopted in the final product. Furthermore, most prior studies ignored the influence of environmental law, goodwill of the product and the efficiency of recycling mechanism of the community.

scholarly journals Transcriptional Profiling Analysis of the Global Regulator NorG, a GntR-Like Protein of Staphylococcus aureus

2011 ◽  
Vol 193 (22) ◽  
pp. 6207-6214 ◽  
Author(s):  
Q. C. Truong-Bolduc ◽  
P. M. Dunman ◽  
T. Eidem ◽  
D. C. Hooper
Keyword(s):  
Staphylococcus Aureus ◽  
Target Genes ◽  
Efflux Pump ◽  
Transcriptional Profiling ◽  
Fold Increase ◽  
Regulatory Function ◽  
Drug Transporter ◽  
Content Type ◽  
Global Regulators ◽  
Inorganic Ion

The GntR-like protein NorG has been shown to affectStaphylococcus aureusgenes involved in resistance to quinolones and β-lactams, such as those encoding the NorB and AbcA transporters. To identify the target genes regulated by NorG, we carried out transcriptional-profiling assays usingS. aureusRN6390 and its isogenicnorG::catmutant. Our data showed that NorG positively affected the transcription of global regulatorsmgrA,arlS, andsarZ. The three putative drug efflux pump genes most positively affected by NorG were the NorB efflux pump (5.1-fold), the MmpL-like protein SACOL2566 (5.2-fold), and the BcrA-like drug transporter SACOL2525 (5.7-fold) genes. TheS. aureuspredicted MmpL protein showed 53% homology with the MmpL lipid transporter ofMycobacterium tuberculosis, and the putative SACOL2525 protein showed 87% homology with the bacitracin drug transporter BcrA ofStaphylococcus hominis. Two pump genes most negatively affected by NorG were the NorC (4-fold) and AbcA (6-fold) genes. Other categories of genes, such as those participating in amino acid, inorganic ion, or nucleotide transporters and metabolism, were also affected by NorG. Real-time reverse transcription (RT)-PCR assays formgrA,arlS,sarZ,norB,norC,abcA,mmpL, andbcrA-like were carried out to verify microarray data and showed the same level of up- or downregulation by NorG. ThenorGmutant showed a 2-fold increase in resistance to norfloxacin and rhodamine, both substrates of the NorC transporter, which is consistent with the resistance phenotype conferred by overexpression ofnorCon a plasmid. These data indicate that NorG has broad regulatory function inS. aureus.

scholarly journals The PedS2/PedR2 Two-Component System Is Crucial for the Rare Earth Element Switch inPseudomonas putidaKT2440

mSphere ◽  
2018 ◽  
Vol 3 (4) ◽  
Author(s):  
Matthias Wehrmann ◽  
Charlotte Berthelot ◽  
Patrick Billard ◽  
Janosch Klebensberger
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Response Regulator ◽  
Regulatory Function ◽  
Methylotrophic Bacteria ◽  
Two Component System ◽  
Component System ◽  
Content Type ◽  
Two Component ◽  
Type Response

ABSTRACTInPseudomonas putidaKT2440, two pyrroloquinoline quinone-dependent ethanol dehydrogenases (PQQ-EDHs) are responsible for the periplasmic oxidation of a broad variety of volatile organic compounds (VOCs). Depending on the availability of rare earth elements (REEs) of the lanthanide series (Ln3+), we have recently reported that the transcription of the genes encoding the Ca2+-utilizing enzyme PedE and the Ln3+-utilizing enzyme PedH are inversely regulated. With adaptive evolution experiments, site-specific mutations, transcriptional reporter fusions, and complementation approaches, we now demonstrate that the PedS2/PedR2 (PP_2671/PP_2672) two-component system (TCS) plays a central role in the observed REE-mediated switch of PQQ-EDHs inP. putida. We provide evidence that in the absence of lanthanum (La3+), the sensor histidine kinase PedS2 phosphorylates its cognate LuxR-type response regulator PedR2, which in turn not only activatespedEgene transcription but is also involved in repression ofpedH. Our data further suggest that the presence of La3+lowers kinase activity of PedS2, either by the direct binding of the metal ions to the periplasmic region of PedS2 or by an uncharacterized indirect interaction, leading to reduced levels of phosphorylated PedR2. Consequently, the decreasingpedEexpression and concomitant alleviation ofpedHrepression causes—in conjunction with the transcriptional activation of thepedHgene by a yet unknown regulatory module—the Ln3+-dependent transition from PedE- to PedH-catalyzed oxidation of alcoholic VOCs.IMPORTANCEThe function of lanthanides for methanotrophic and methylotrophic bacteria is gaining increasing attention, while knowledge about the role of rare earth elements (REEs) in nonmethylotrophic bacteria is still limited. The present study investigates the recently described differential expression of the two PQQ-EDHs ofP. putidain response to lanthanides. We demonstrate that a specific TCS is crucial for their inverse regulation and provide evidence for a dual regulatory function of the LuxR-type response regulator involved. Thus, our study represents the first detailed characterization of the molecular mechanism underlying the REE switch of PQQ-EDHs in a nonmethylotrophic bacterium and stimulates subsequent investigations for the identification of additional genes or phenotypic traits that might be coregulated during REE-dependent niche adaptation.

scholarly journals Evolutionary Plasticity of AmrZ Regulation in Pseudomonas

mSphere ◽  
2018 ◽  
Vol 3 (2) ◽  
pp. e00132-18 ◽  
Author(s):  
David A. Baltrus ◽  
Kevin Dougherty ◽  
Beatriz Diaz ◽  
Rachel Murillo
Keyword(s):  
Pseudomonas Syringae ◽  
Negative Regulator ◽  
Regulatory Function ◽  
Dual Function ◽  
Genomic Context ◽  
Master Regulator ◽  
Content Type ◽  
Swimming Motility ◽  
Positive Regulator ◽  
Mode Of Regulation

ABSTRACT amrZ encodes a master regulator protein conserved across pseudomonads, which can be either a positive or negative regulator of swimming motility depending on the species examined. To better understand plasticity in the regulatory function of AmrZ, we characterized the mode of regulation for this protein for two different motility-related phenotypes in Pseudomonas stutzeri. As in Pseudomonas syringae, AmrZ functions as a positive regulator of swimming motility within P. stutzeri, which suggests that the functions of this protein with regard to swimming motility have switched at least twice across pseudomonads. Shifts in mode of regulation cannot be explained by changes in AmrZ sequence alone. We further show that AmrZ acts as a positive regulator of colony spreading within this strain and that this regulation is at least partially independent of swimming motility. Closer investigation of mechanistic shifts in dual-function regulators like AmrZ could provide unique insights into how transcriptional pathways are rewired between closely related species. IMPORTANCE Microbes often display finely tuned patterns of gene regulation across different environments, with major regulatory changes controlled by a small group of “master” regulators within each cell. AmrZ is a master regulator of gene expression across pseudomonads and can be either a positive or negative regulator for a variety of pathways depending on the strain and genomic context. Here, we demonstrate that the phenotypic outcomes of regulation of swimming motility by AmrZ have switched at least twice independently in pseudomonads, so that AmrZ promotes increased swimming motility in P. stutzeri and P. syringae but represses this phenotype in Pseudomonas fluorescens and Pseudomonas aeruginosa. Since examples of switches in regulatory mode are relatively rare, further investigation into the mechanisms underlying shifts in regulator function for AmrZ could provide unique insights into the evolution of bacterial regulatory proteins.

Germinating seeds in dry soil: examining the process of frugal innovation in micro- and small-enterprises at the base of the pyramid

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Miriam Borchardt ◽  
Charbel José Chiappetta Jabbour ◽  
José de Figueiredo Belém ◽  
Venkatesh Mani ◽  
Giancarlo Medeiros Pereira ◽  
...  
Keyword(s):  
Business Models ◽  
Raw Materials ◽  
Life Cycles ◽  
Small Enterprises ◽  
Base Of The Pyramid ◽  
Frugal Innovation ◽  
Content Type ◽  
Fashion Products ◽  
Poor Region ◽  
Micro And Small Enterprises

Purpose This study aims to examine the process of frugal innovation (FI) in micro- and small-enterprises (MSEs) at the base of the pyramid (BOP) through the analytical lens of business models. Design/methodology/approach A case study was conducted with 30 MSEs from three different industries in a very poor region in Brazil. Findings The findings indicate that, in cases where FI is intense and dynamic, the start of the FI process is based on the reinterpretation of fashion trends and influences from the business ecosystem while the consolidation of FI in MSEs occurs through the reconfiguration of resources. Additionally, this study shows that FI depends on conditions other than the production of frugal products for BOP consumers. Research limitations/implications This study points out that the presence of end-of-life non-BOP raw materials distributed by large distributors in the case of fashion products, along with the interaction between MSEs at the BOP and these distributors, trigger FI and are profitable for both. For non-fashion products with long life cycles, there is no demand for innovation. Originality/value This study addresses the research void present in the literature on FI by presenting the process of FI and the conditions that leverage or stagnate FI in MSEs at the BOP, as well as how business models are shaped by these conditions.

scholarly journals Blakeslea trispora Photoreceptors: Identification and Functional Analysis

2020 ◽  
Vol 86 (8) ◽  
Author(s):  
Wei Luo ◽  
Chao Xue ◽  
Yuzheng Zhao ◽  
Huili Zhang ◽  
Zhiming Rao ◽  
...  
Keyword(s):  
Large Scale ◽  
Binding Domain ◽  
Site Directed Mutagenesis ◽  
Flavin Mononucleotide ◽  
Blakeslea Trispora ◽  
Scale Production ◽  
Bioinformatics Analyses ◽  
Content Type ◽  
Flavin Binding

ABSTRACT Blakeslea trispora is an industrial fungal species used for large-scale production of carotenoids. However, B. trispora light-regulated physiological processes, such as carotenoid biosynthesis and phototropism, are not fully understood. In this study, we isolated and characterized three photoreceptor genes, btwc-1a, btwc-1b, and btwc-1c, in B. trispora. Bioinformatics analyses of these genes and their protein sequences revealed that the functional domains (PAS/LOV [Per-ARNT-Sim/light-oxygen-voltage] domain and zinc finger structure) of the proteins have significant homology to those of other fungal blue-light regulator proteins expressed by Mucor circinelloides and Neurospora crassa. The photoreceptor proteins were synthesized by heterologous expression in Escherichia coli. The chromogenic groups consisting of flavin adenine dinucleotide (FAD) and flavin mononucleotide (FMN) were detected to accompany BTWC-1 proteins by using high-performance liquid chromatography (HPLC) and fluorescence spectrometry, demonstrating that the proteins may be photosensitive. The absorbance changes of the purified BTWC-1 proteins seen under dark and light conditions indicated that they were light responsive and underwent a characteristic photocycle by light induction. Site-directed mutagenesis of the cysteine residual (Cys) in BTWC-1 did not affect the normal expression of the protein in E. coli but did lead to the loss of photocycle response, indicating that Cys represents a flavin-binding domain for photon detection. We then analyzed the functions of BTWC-1 proteins by complementing btwc-1a, btwc-1b, and btwc-1c into the counterpart knockout strains of M. circinelloides for each mcwc-1 gene. Transformation of the btwc-1a complement into mcwc-1a knockout strains restored the positive phototropism, while the addition of btwc-1c complement remedied the deficiency of carotene biosynthesis in the mcwc-1c knockout strains under conditions of illumination. These results indicate that btwc-1a and btwc-1c are involved in phototropism and light-inducible carotenogenesis. Thus, btwc-1 genes share a conserved flavin-binding domain and act as photoreceptors for control of different light transduction pathways in B. trispora. IMPORTANCE Studies have confirmed that light-regulated carotenogenesis is prevalent in filamentous fungi, especially in mucorales. However, few investigations have been done to understand photoinduced synthesis of carotenoids and related mechanisms in B. trispora, a well-known industrial microbial strains. In the present study, three photoreceptor genes in B. trispora were cloned, expressed, and characterized by bioinformatics and photoreception analyses, and then in vivo functional analyses of these genes were constructed in M. circinelloides. The results of this study will lead to a better understanding of photoreception and light-regulated carotenoid synthesis and other physiological responses in B. trispora.

Sign in / Sign up

Export Citation Format

Share Document