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This study examines the role of relationship marketing on Small and Medium Enterprises (SMEs) in Indonesia. Relationship marketing is a concept in marketing management aimed at maintaining long-term relationships with customers. Meanwhile, SMEs occupy a crucial role in sustaining the economy of Indonesia. Therefore, by implementing the concept of relationship marketing, it is expected that customer loyalty on SMEs is formed and can maintain the sustainability of SMEs. The study used survey methods, with a sample pool of 183 SMEs customers. The analysis technique utilized structural equation modeling (SEM) and the data was processed using AMOS Basic. The results show that trust and relational commitment is significantly affected by communication and relational benefits. Meanwhile, trust and relational commitment significantly affect customer loyalty. The variables of similarity and frequency of interactions have no significant effect on either trust or relational commitment of customers of SMEs. [ABSTRACT FROM AUTHOR]

Background: Gram-positive bacteria of the Bacillales are important producers of antimicrobial compounds that might be utilized for medical, food or agricultural applications. Thanks to the wide availability of whole genome sequence data and the development of specific genome mining tools, novel antimicrobial compounds, either ribosomally- or non-ribosomally produced, of various Bacillales species can be predicted and classified. Here, we provide a classification scheme of known and putative antimicrobial compounds in the specific context of Bacillales species. Results: We identify and describe known and putative bacteriocins, non-ribosomally synthesized peptides (NRPs), polyketides (PKs) and other antimicrobials from 328 whole-genome sequenced strains of 57 species of Bacillales by using web based genome-mining prediction tools. We provide a classification scheme for these bacteriocins, update the findings of NRPs and PKs and investigate their characteristics and suitability for biocontrol by describing per class their genetic organization and structure. Moreover, we highlight the potential of several known and novel antimicrobials from various species of Bacillales. Conclusions: Our extended classification of antimicrobial compounds demonstrates that Bacillales provide a rich source of novel antimicrobials that can now readily be tapped experimentally, since many new gene clusters are identified [ABSTRACT FROM AUTHOR]

Aim The study mainly aimed the isolation and characterization of plant probiotic endophytic bacteria from Capsicum annuum to explore its multipotent agricultural applications. Materials and Methods Endophytic bacteria were isolated from the surface sterilized fruit tissue. The isolates were then subjected to PCR-based screening for the presence of potential biosynthetic gene clusters. The PCR positive isolate was then analysed for its inhibitory effect towards fungal and bacterial pathogens. The compounds responsible for the antimicrobial activity was purified from large scale culture and subjected to identification by LC- MS/ MS. The ability of the selected isolate in plant growth enhancement was also done using Vigna radiata seedlings. Conclusion In this study, an endophytic bacterium isolated from C. annuum was found to have the phenotypic and genetic basis for broad antimicrobial property. PCR-based sequence analysis has resulted in the identification of nonribosomal peptide synthases, PKS Type I, Iturin, surfactin, DAPG and gacA genes in the selected isolate CaB 5. The bioactivity-guided fractionation using column and HPLC purification of active fraction followed by LC- MS/ MS analysis has proved the presence of surfactin derivatives (M+H+ - 1008 & 1036) and iturin (M+H+ - 1058) as the basis of antimicrobial activity of CaB 5. The isolate was identified as a novel Bacillus sp. because of its low (76%) identity to the reported sequences. Significance and Impact of the study Endophytes are considered to have the genetic basis for a diverse array of bioactive metabolites which can have significant applications in both pharmaceutical industry and agriculture. The identification of CaB 5 with broad bioactivity and excellent plant growth enhancement on taxonomically distinct plant species as explained in current study and our previous reports highlights its plant probiotic applicability. This proves the potential of the isolate obtained in the study to be an excellent plant probiotic. [ABSTRACT FROM AUTHOR]

Celem niniejszego artykułu jest przedstawienie 25-letnich przekształceń organizacyjno-własnościowych narodowych przedsiębiorstw transportu samochodowego w Polsce (PKS), w Czechach i na Słowacji (ČSAD) oraz na Węgrzech (Volán). Artykuł składa się z dwóch części. W części I, w niniejszym zeszycie, opisuje się genezę i rozwój narodowych przewoźników drogowych, ramy prawne i warunki ich prywatyzacji, a także charakterystykę transformacji samochodowych przedsiębiorstw towarowych. Część II, która ukaże się w zeszycie 2/2017 Przeglądu Geograficznego, koncentruje się na przekształceniach przedsiębiorstw transportu autobusowego w krajach Grupy Wyszehradzkiej. [ABSTRACT FROM AUTHOR]

Natural products are often secondary metabolites in living organisms with a wide variety of biological activities. The diversification of their structures, aiming to the search for biologically active small molecules by expanding chemical and functional spaces, is a major area of current interest in synthetic chemistry. However, developing synthetic accessibility and efficiency often faces challenges associated with structural complexity. Synthetic biology has recently emerged and is promising to accomplish complex molecules; by contrast, the application to structural diversification of natural products relies on the understanding, development and utilization of compatible biosynthetic machinery. Here, we review the strategies primarily concerning the artificial evolution of microbial natural products whose biosynthesis features template enzymology, including ribosomally synthesized and post-translationally modified peptides as well as the assembly line-resultant polyketides, non-ribosomal peptides and hybrids. The establishment of these approaches largely facilitates the expansion of the molecular diversity and utility through bioengineering at different stages/levels of biosynthetic pathways. [ABSTRACT FROM AUTHOR]

Copyright of Studia Islamika is the property of Center for the Study of Islam & Society of UIN Jakarta and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Trichoderma species are widely used in agriculture as biofungicides. These fungi are rich source of secondary metabolites and the mycoparasitic species are enriched in genes for biosynthesis of secondary metabolites. Most often, genes for secondary metabolism are clustered in fungal genomes. Previously, no systematic study was undertaken to identify the secondary-metabolism related gene clusters in Trichoderma genomes. In the present study, a survey of the three Trichoderma genomes viz. T. reesei, T. atroviride and T. virens, was made to identify the putative gene clusters associated with secondary metabolism. In T. reesei genome, we identified one new NRPS and 6 new PKS clusters, which is much less than that found in T. atroviride (4 and 8) and T. virens (8 and 7). This work would pave the way for discovery of novel secondary metabolites and pathways in Trichoderma. [ABSTRACT FROM AUTHOR]

Two new members of the amphidinol family, amphidinol A (1) and its 7-sulfate derivative amphidinol B (2), were isolated from a strain of Amphidinium carterae of Lake Fusaro, near Naples (Italy), and chemically identified by spectroscopic and spectrometric methods. Amphidinol A showed antifungal activity against Candida albicans (MIC = 19 µg/mL). Biosynthetic experiments with stable isotope-labelled acetate allowed defining the elongation process in 1. For the first time the use of glycolate as a starter unit in the polyketide biosynthesis of amphidinol metabolites was unambiguously demonstrated.

Microbial secondary metabolites have been an important source of bioactive compounds with diverse applications from medicine to agriculture, noticeably those encoded by polyketide synthase (PKS) clusters due to their astounding chemical diversity. While most discovered compounds originate from culturable microorganisms, yet-to-be cultured microbes represent a reservoir of previously inaccessible compounds. The advent and development of metagenomics have allowed not only the characterization of these microorganisms but also their metabolic potential, making viable the prospection of environmental PKS for natural product discovery.Study of environmental PKSs often relies on the construction of metagenomic libraries and their mining, with clones containing PKS clusters identified via amplification of conserved domains and then screened for an activity of interest. Compounds produced by clones exhibiting the desired bioactivity can be isolated and characterized. However, these approaches can be less sensitive and biased against more divergent clusters, in addition to precluding the use of bioinformatics for cluster characterization prior to expression. While direct shotgun sequencing of metagenomes has identified and profiled a great number of PKSs from different environments and yet-to-be cultured microorganisms, it does not lend itself well to heterologous expression, the cruxes of natural product discovery.Here, we describe a strategy for sequencing entire metagenomic libraries while maintaining correspondence between sequence and clone, allowing the full characterization and annotation of all clusters present in a library using bioinformatic tools and then seamlessly passing clones of interest for activity screening through heterologous expression. Once a library is sequenced, the methods herein can be adapted for the mining of any biosynthetic gene cluster of interest within a metagenomic library., (© 2023. The Author(s), under exclusive license to Springer Science+Business Media, LLC, part of Springer Nature.)

Marine environments harbor a wide range of microorganisms from the three domains of life. These microorganisms have great potential to enable discovery of new enzymes and bioactive compounds for industrial use. However, only ~1% of microorganisms from the environment can currently be identified through cultured isolates, limiting the discovery of new compounds. To overcome this limitation, a metagenomics approach has been widely adopted for biodiversity studies on samples from marine environments. In this study, we screened metagenomes in order to estimate the potential for new natural compound synthesis mediated by diversity in the Polyketide Synthase (PKS) and Nonribosomal Peptide Synthetase (NRPS) genes. The samples were collected from the Praia dos Anjos (Angel's Beach) surface water-Arraial do Cabo (Rio de Janeiro state, Brazil), an environment affected by upwelling. In order to evaluate the potential for screening natural products in Arraial do Cabo samples, we used KS (keto-synthase) and C (condensation) domains (from PKS and NRPS, respectively) to build Hidden Markov Models (HMM) models. From both samples, a total of 84 KS and 46 C novel domain sequences were obtained, showing the potential of this environment for the discovery of new genes of biotechnological interest. These domains were classified by phylogenetic analysis and this was the first study conducted to screen PKS and NRPS genes in an upwelling affected sample [ABSTRACT FROM AUTHOR]

Copyright of Monatsschrift fuer Kriminologie und Strafrechtsreform is the property of De Gruyter and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Continental Portugal has an extensive Atlantic Ocean coastline; however little is known about the diversity of its marine cyanobacteria, with only a few reports published. Cyanobacteria are a prolific source of bioactive compounds with promising therapeutic applications. Previously, several cyanobacterial strains (Subsections I–IV) were isolated from the Portuguese Atlantic coast and characterized using a polyphasic approach. Preliminary screening indicated that these cyanobacteria lacked the genes for proteins involved in the production of conventional cyanotoxins. However, it was previously shown that extracts of marine Synechocystis and Synechococcus were toxic to invertebrates, with crude extracts causing stronger effects than partially purified ones. To further evaluate the potential of our temperate region Portuguese isolates to produce bioactive compounds, a PCR screening for the presence of genes encoding non-ribosomal peptide synthetases (NRPSs) and polyketide synthases (PKSs), targeting the adenylation (A) and ketosynthase (KS) domains respectively, was performed. DNA fragments were obtained for more than 80% of the strains tested, and the results revealed that PKS genes are more ubiquitous than NRPS genes. The sequences obtained were used in an in silico prediction of the PKS and NRPS systems. RT-PCR analyses revealed that these genes are transcribed under routine laboratory conditions in several selected strains. Furthermore, LC–MS analysis coupled with molecular networking, a mass spectrometric tool that clusters metabolites with similar MS/MS fragmentation patterns, was used to search for novel or otherwise interesting metabolites revealing an untapped chemodiversity. [ABSTRACT FROM AUTHOR]

Members of the genus Fusarium produce a plethora of bioactive secondary metabolites, which can be harmful to humans and animals or have potential in drug development. In this study we have performed comparative analyses of polyketide synthases ( PKSs ) and non-ribosomal peptide synthetases ( NRPSs ) from ten different Fusarium species including F. graminearum (two strains), F. verticillioides , F. solani , F. culmorum , F. pseudograminearum , F. fujikuroi , F. acuminatum , F. avenaceum , F. equiseti , and F. oxysporum (12 strains). This led to identification of 52 NRPS and 52 PKSs orthology groups, respectively, and although not all PKSs and NRPSs are assumed to be intact or functional, the analyses illustrate the huge secondary metabolite potential in Fusarium . In our analyses we identified a core collection of eight NRPSs ( NRPS2 – 4 , 6 , 10 – 13 ) and two PKSs ( PKS3 and PKS7 ) that are conserved in all strains analyzed in this study. The identified PKSs and NRPSs were named based on a previously developed classification system ( www.FusariumNRPSPKS.dk ). We suggest this system be used when PKSs and NRPSs have to be classified in future sequenced Fusarium strains. This system will facilitate identification of orthologous and non-orthologous NRPSs and PKSs from newly sequenced Fusarium genomes and will aid the scientific community by providing a common nomenclature for these two groups of genes/enzymes. [ABSTRACT FROM AUTHOR]

Soil bacteria can be prolific producers of secondary metabolites and other biologically active compounds of economic and clinical importance. These natural products are often synthesized by large multi-enzyme complexes such as polyketide synthases (PKSs) or non-ribosomal peptide synthases (NRPSs). The plant-associated Gram-negative bacterium, Serratia plymuthica A153, produces several secondary metabolites and is capable of killing the nematode worm Caenorhabditis elegans; a commonly used model for the study of bacterial virulence. In this study, we show that disruption of the hybrid PKS/NRPS zeamine (zmn) gene cluster results in the attenuation of "fast-killing" of C. elegans, indicating that zeamine has nematicidal activity. C. elegans also exhibits age-dependent susceptibility to zeamine, with younger worms being most sensitive to the bioactive molecule. The zmn gene cluster is widely distributed within Serratia and phytopathogenic Dickeya species and investigation of strains harboring the zmn gene cluster showed that several of them are highly virulent in C. elegans. Zeamine was described previously as a phytotoxin and broadspectrum antibacterial compound. In addition to its nematicidal properties, we show here that zeamine can also kill Saccharomyces cerevisiae and Schizosaccharomyces pombe. The expression of the zmn gene cluster and regulation of zeamine production were also investigated. Transcription of the cluster was growth phase-dependent, and was modulated by the post-transcriptional RNA chaperone, Hfq. The results of this study show that zeamine is a highly toxic molecule with little, or no, apparent host specificity in very diverse biological systems. In its current form, zeamine(s) may be useful as a lead compound suitable for chemical modification and structure-activity assays. However, because of widespread nonselective toxicity in multiple bioassays, unmodified zeamine(s) is unlikely to be suitable as a therapeutic antibiotic. [ABSTRACT FROM AUTHOR]

Non-ribosomal peptide (NRP) synthesis in fungi requires a ready supply of proteogenic and non-proteogenic amino acids which are subsequently incorporated into the nascent NRP via a thiotemplate mechanism catalyzed by NRP synthetases. Substrate amino acids can be modified prior to or during incorporation into the NRP, or following incorporation into an early stage amino acid-containing biosynthetic intermediate. These post-incorporation modifications involve a range of additional enzymatic activities including but not exclusively, monooxygenases, methyltransferases, epimerases, oxidoreductases, and glutathione S-transferases which are essential to effect biosynthesis of the final NRP. Likewise, polyketide biosynthesis is directly by polyketide synthase megaenzymes and cluster-encoded ancillary decorating enzymes. Additionally, a suite of additional primary metabolites, for example: coenzyme A (CoA), acetyl CoA, S-adenosylmethionine, glutathione (GSH), NADPH, malonyl CoA, and molecular oxygen, amongst others are required for NRP and polyketide synthesis (PKS). Clearly these processes must involve exquisite orchestration to facilitate the simultaneous biosynthesis of different types of NRPs, polyketides, and related metabolites requiring identical or similar biosynthetic precursors or co-factors. Moreover, the near identical structures of many natural products within a given family (e.g., ergot alkaloids), along with localization to similar regions within fungi (e.g., conidia) suggests that cross-talk may exist, in terms of biosynthesis and functionality. Finally, we speculate if certain biosynthetic steps involved in NRP and PKS play a role in cellular protection or environmental adaptation, and wonder if these enzymatic reactions are of equivalent importance to the actual biosynthesis of the final metabolite. [ABSTRACT FROM AUTHOR]

This essay tries to critically evaluate a way of thinking developed among Salafi leader dan PKS as a movement of Islamic revivalism which related to the implementation of Islamic law (syari’ah) into the Indonesian democracy context. There are a number of critical notes was discovered from literary researches and interviews with several leader of the movement. Firstly, basicly both PKS and Salafi leader longing for the implementation of Islamic law in the Indonesian democracy context. Despite the fact that PKS tend to act disparagingly toward democracy, while Salafi clearly repudiate democracy system, however, both of this group agree to “manipulate” this system to strugle for the embodiment of Islamic law with different strategies and substance. Secondly, PKS enters this system while trying to “objectify” Islamic values through preaching dan politics (structurally and culturally). In the same vein, Salafi manipulates democracy to strenghthen their ideological basis and their Islamic puritans awareness through preaching. Regarding politics, Salafi tends to be “pasive”. Lastly, there are indications that the idea of the Islamic law implementation among PKS leader has dynamically changed following the politics dynamics. This often percieved as an inconsistency by the society. Meanwhile, the idea and efforts to implement Islamic law among Salafi leader is limited to the area of family rule and rarely about public rules. The result of this critical evaluation upon the implementation of Islamic law done by PKS and Salafi leaders, up to this point, have not provide a viable recomendation as an ideal model of strengthening democracy system and implementing Islamic law in Indonesia.

Fusarielins are polyketides with a decalin core produced by various species of Aspergillus and Fusarium. Although the responsible gene cluster has been identified, the biosynthetic pathway remains to be elucidated. In the present study, members of the gene cluster were deleted individually in a Fusarium graminearum strain overexpressing the local transcription factor. The results suggest that a trans-acting enoyl reductase (FSL5) assists the polyketide synthase FSL1 in biosynthesis of a polyketide product, which is released by hydrolysis by a trans-acting thioesterase (FSL2). Deletion of the epimerase (FSL3) resulted in accumulation of an unstable compound, which could be the released product. A novel compound, named prefusarielin, accumulated in the deletion mutant of the cytochrome P450 monooxygenase FSL4. Unlike the known fusarielins from Fusarium, this compound does not contain oxygenized decalin rings, suggesting that FSL4 is responsible for the oxygenation.

The Macau storage reservoir (MSR) has experienced algal blooms in recent years, with high levels of Cylindrospermopsis and Microcystis and detectable concentrations of cyanotoxins. To analyze the cyanotoxin-producing genotypes and relate the corresponding cyanotoxins to the water quality parameters, a quantitative real-time polymerase chain reaction was developed and applied to the water samples in three locations of MSR. Cylindrospermopsin polyketide synthetase ( pks) gene and a series of microcystin synthetase ( mcy) genes were used for identifying and quantifying cylindrospermopsin- and microcystin-producing genes, and the corresponding water parameters were measured accordingly. Our results showed that high concentrations of cylindrospermopsin and low concentrations of microcystin were measured during the study period. There was a strong correlation between the pks gene numbers and cylindrospermopsin concentrations ( R = 0.95), while weak correlations were obtained between the mcy genes numbers and microcystin concentrations. Furthermore, the pks gene numbers were strongly related to Cylindrospermopsis ( R = 0.88), cyanobacterial cell numbers ( R = 0.96), total algae numbers ( R = 0.95), and chlorophyll- a concentrations ( R = 0.83), consistent with the dominant species of Cylindrospermopsis among the cyanobacteria existing in MSR. NH-N ( R = 0.68) and pH ( R = 0.89) were the water quality parameters most highly correlated with the pks gene numbers. These results contribute to monitoring for potential cyanotoxins in raw water. [ABSTRACT FROM AUTHOR]

Background Cyanobacteria are an ancient lineage of photosynthetic bacteria from which hundreds of natural products have been described, including many notorious toxins but also potent natural products of interest to the pharmaceutical and biotechnological industries. Many of these compounds are the products of non-ribosomal peptide synthetase (NRPS) or polyketide synthase (PKS) pathways. However, current understanding of the diversification of these pathways is largely based on the chemical structure of the bioactive compounds, while the evolutionary forces driving their remarkable chemical diversity are poorly understood. Results We carried out a phylum-wide investigation of genetic diversification of the cyanobacterial NRPS and PKS pathways for the production of bioactive compounds. 452 NRPS and PKS gene clusters were identified from 89 cyanobacterial genomes, revealing a clear burst in latebranching lineages. Our genomic analysis further grouped the clusters into 286 highly diversified cluster families (CF) of pathways. Some CFs appeared vertically inherited, while others presented a more complex evolutionary history. Only a few horizontal gene transfers were evidenced amongst strongly conserved CFs in the phylum, while several others have undergone drastic gene shuffling events, which could result in the observed diversification of the pathways. Conclusions Therefore, in addition to toxin production, several NRPS and PKS gene clusters are devoted to important cellular processes of these bacteria such as nitrogen fixation and iron uptake. The majority of the biosynthetic clusters identified here have unknown end products, highlighting the power of genome mining for the discovery of new natural products. [ABSTRACT FROM AUTHOR]

There is a substantial interest in the adoption of e-commerce by firms, particularly the small and medium enterprises (SMEs). SMEs are said to gain considerably from using the e-commerce because the Internet provides equal access to both SMEs and large organizations. It is also said SMEs which adopt e-commerce will improve their businesses and finally increase their profit. However, little is known concerning the benefits that SMEs have gained by adopting e-commerce and to what extent have SMEs achieved these benefits. Thus, this paper aims to analyse between the benefits that SMEs perceived they have gained and the proven benefits they realised. Survey and face-to-face interviews were carried-out in this study. The study found a number of interesting facts. Many respondents in the survey indicated that they gained some benefits, such as, more customers, increased sales, and increased productivity. Yet, the interviews did not substantiate such claims. This paper looks at these views critically and finally provides some suggestions and recommendations. [ABSTRACT FROM AUTHOR]

Creating high employee engagement is becoming more important in achieving sustainability in small and medium enterprises (SMEs). It helps organisations to motivate their employees to go beyond expectation. The main characteristic of organisation that pursues sustainability includes creating ethical values through organisational climate. This paper analyses the impact of ethical work climate on employee engagement and organisational citizenship behavior (OCB). Study was conducted on SMEs in Central Java, Indonesia. This research utilised quantitative approach and data collection was based on survey questionnaire. The result highlighted the significant impact of ethical work climate on employee engagement and OCB. This study's findings contribute to the business ethics and SME literature by providing relevant empirical evidence based on primary data. The results provide guidance to SMEs in achieving sustainability. [ABSTRACT FROM AUTHOR]

L. pneumophila- containing vacuoles (LCVs) exclude endocytic and lysosomal markers in human macrophages and protozoa. We screened a L. pneumophila mini-Tn10 transposon library for mutants, which fail to inhibit the fusion of LCVs with lysosomes by loading of the lysosomal compartment with colloidal iron dextran, mechanical lysis of infected host cells, and magnetic isolation of LCVs that have fused with lysosomes. In silico analysis of the mutated genes, D. discoideum plaque assays and infection assays in protozoa and U937 macrophage-like cells identified well established as well as novel putative L. pneumophila virulence factors. Promising candidates were further analyzed for their co-localization with lysosomes in host cells using fluorescence microscopy. This approach corroborated that the O -methyltransferase, PilY1, TPR-containing protein and polyketide synthase (PKS) of L. pneumophila interfere with lysosomal degradation. Competitive infections in protozoa and macrophages revealed that the identified PKS contributes to the biological fitness of pneumophila strains and may explain their prevalence in the epidemiology of Legionnaires’ disease. [ABSTRACT FROM AUTHOR]

Sponge-associated microorganisms are able to assemble the complex machinery for the production of secondary metabolites such as polyketides, the most important class of marine natural products from a drug discovery perspective. A comprehensive overview of polyketide biosynthetic genes of the sponge Plakortis halichondrioides and its symbionts was obtained in the present study by massively parallel 454 pyrosequencing of complex and heterogeneous PCR (Polymerase Chain Reaction) products amplified from the metagenomic DNA of a specimen of P. halichondrioides collected in the Caribbean Sea. This was accompanied by a survey of the bacterial diversity within the sponge. In line with previous studies, sequences belonging to supA and swfA, two widespread sponge-specific groups of polyketide synthase (PKS) genes were dominant. While they have been previously reported as belonging to Poribacteria (a novel bacterial phylum found exclusively in sponges), re-examination of current genomic sequencing data showed supA and swfA not to be present in the poribacterial genome. Several non-supA, non-swfA type-I PKS fragments were also identified. A significant portion of these fragments resembled type-I PKSs from protists, suggesting that bacteria may not be the only source of polyketides from P. halichondrioides, and that protistan PKSs should receive further investigation as a source of novel polyketides. [ABSTRACT FROM AUTHOR]

The diversity and properties of actinobacteria, predominant residents in coral holobionts, have been rarely documented. In this study, we aimed to explore the species diversity, antimicrobial activities and biosynthetic potential of culturable actinomycetes within the tissues of the scleractinian corals Porites lutea, Galaxea fascicularis and Acropora millepora from the South China Sea. A total of 70 strains representing 13 families and 15 genera of actinobacteria were isolated. The antimicrobial activity and biosynthetic potential of fifteen representative filamentous actinomycetes were estimated. Crude fermentation extracts of 6 strains exhibited comparable or greater activities against Vibrio alginolyticus than ciprofloxacin. Seven of the 15 actinomycetes strains possess type I polyketide synthases (PKS-I) and/or nonribosomal peptide synthetases (NRPS) genes. Nine tested strains possess type II polyketide synthases (PKS-II). Phylogenetic analysis based on 16S rRNA gene sequences indicated that these PKS and NRPS gene screening positive strains belong to genera Nocardiopsis, Pseudonocardia, Streptomyces, Micromonospora, Amycolatopsis and Prauserella. One PKS-I and four NRPS fragments showed <70 % similarity to their closest relatives, which suggested the novelty of these genes. This study helps uncover the genetic capacity of stony coral-associated actinomycetes to produce bioactive molecules. [ABSTRACT FROM AUTHOR]

A large number of antibiotics and other industrially important microbial secondary metabolites are synthesized by polyketide synthases (PKSs) and nonribosomal peptide synthetases (NRPSs). These multienzymatic complexes provide an enormous flexibility in formation of diverse chemical structures from simple substrates, such as carboxylic acids and amino acids. Modular PKSs and NRPSs, often referred to as megasynthases, have brought about a special interest due to the colinearity between enzymatic domains in the proteins working as an 'assembly line' and the chain elongation and modification steps. Extensive efforts toward modified compound biosynthesis by changing organization of PKS and NRPS domains in a combinatorial manner laid good grounds for rational design of new structures and their controllable biosynthesis as proposed by the synthetic biology approach. Despite undeniable progress made in this field, the yield of such 'unnatural' natural products is often not satisfactory. Here, we focus on type II thioesterases (TEIIs)-discrete hydrolytic enzymes often encoded within PKS and NRPS gene clusters which can be used to enhance product yield. We review diverse roles of TEIIs (removal of aberrant residues blocking the megasynthase, participation in substrate selection, intermediate, and product release) and discuss their application in new biosynthetic systems utilizing PKS and NRPS parts. [ABSTRACT FROM AUTHOR]

Abstract: Ochratoxin A (OTA) is a potent mycotoxin produced by Aspergillus and Penicillium species and is a common contaminant of a wide variety of food commodities, with Aspergillus carbonarius being the main producer of OTA contamination in grapes and wine. The molecular structure of OTA comprises a dihydroisocoumarin ring linked to phenylalanine and, as shown in different producing fungal species, a polyketide synthase (PKS) is a component of the OTA biosynthetic pathway. Similar to observations in other filamentous ascomycetes, the genome sequence of A. carbonarius contains a large number of genes predicted to encode PKSs. In this work a pks gene identified within the putative OTA cluster of A. carbonarius, designated as AcOTApks, was inactivated and the resulting mutant strain was unable to produce OTA, confirming the role of AcOTApks in this biosynthetic pathway. AcOTApks protein is characteristic of the highly reduced (HR)-PKS family, and also contains a putative methyltransferase domain likely responsible for the addition of the methyl group to the OTA polyketide structure. AcOTApks is different from the ACpks protein that we previously described in A. carbonarius, which showed an expression profile compatible with OTA production. We performed phylogenetic analyses of the β-ketosynthase and acyl-transferase domains of the OTA PKSs that had been identified and characterized in different OTA producing fungal species. The phylogenetic results were similar for both domains analyzed and showed that OTA PKS of A. carbonarius, Aspergillus niger and Aspergillus ochraceus clustered in a monophyletic group with 100% bootstrap support suggesting a common origin, while the other OTA PKSs analyzed were phylogenetically distant. A quantitative RT-PCR assay monitored AcOTApks expression during fungal growth and concomitant production of OTA by A. carbonarius in synthetic grape medium. A clear correlation between the expression profile of AcOTApks and kinetics of OTA production was observed, with AcOTApks reaching its maximum level of transcription before OTA accumulation in mycelium reached its highest level, confirming the fact that gene transcription always precedes phenotypic production. [Copyright &y& Elsevier]

Background The pectinolytic enterobacteria of the Pectobacterium and Dickeya genera are causative agents of maceration-associated diseases affecting a wide variety of crops and ornamentals. For the past decade, the emergence of a novel species D. solani was observed in potato fields in Europe and the Mediterranean basin. The purpose of this study is to search by comparative genomics the genetic traits that could be distinctive to other Dickeya species and be involved in D. solani adaptation to the potato plant host. Results D. solani 3337 exhibits a 4.9 Mb circular genome that is characterized by a low content in mobile elements with the identification of only two full length insertion sequences. A genomic comparison with the deeply-annotated model D. dadantii 3937 strain was performed. While a large majority of Dickeya virulence genes are shared by both strains, a few hundreds genes of D. solani 3337, mostly regrouped in 25 genomic regions, are distinctive to D. dadantii 3937. These genomic regions are present in the other available draft genomes of D. solani strains and interestingly some of them were not found in the sequenced genomes of the other Dickeya species. These genomic regions regroup metabolic genes and are often accompanied by genes involved in transport systems. A metabolic analysis correlated some metabolic genes with distinctive functional traits of both D. solani 3337 and D. dadantii 3937. Three identified D. solani genomic regions also regroup NRPS/PKS encoding genes. In addition, D. solani encodes a distinctive arsenal of T5SS and T6SSrelated toxin-antitoxin systems. These genes may contribute to bacteria-bacteria interactions and to the fitness of D. solani to the plant environment. Conclusions This study highlights the genomic specific traits of the emerging pathogen D. solani and will provide the basis for studying those that are involved in the successful adaptation of this emerging pathogen to the potato plant host. [ABSTRACT FROM AUTHOR]

An important objective in alfalfa breeding is the improvement of forage quality. The aim of this experiment was to determine the genetic control of the most important quality traits in whole plant leaves and stems of alfalfa genotypes. Quantitative genetic parameters were estimated for crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF) and acid detergent lignin (ADL) content. A 5x5 diallel design with reciprocals among parents from geographically different populations were studied. In the diallel study, effects due to general combining ability (GCA) were higher than those due to specific combining ability (SCA) for majority of the tested characters in analyses of whole plant. The F1 progeny effect was significant for almost all characters (except ADF content). The highest values of narrow sense heritability's were found for NDF (h =0.19) and CP (h =0.17) in whole plant, and in leaves (0.11 and 0.08), while in stems most heritable traits are ADF (h = 0.29) and ADL (h = 0.16) content. As a consequence, CP, NDF and ADF content would be more efficient selection criteria in whole plant analyses, while ADF and ADL content would be more interesting to investigate in stems, in a breeding program for improved nutritive value of alfalfa. [ABSTRACT FROM AUTHOR]

Microbial genome mining is a rapidly developing approach to discover new and novel secondary metabolites for drug discovery. Many advances have been made in the past decade to facilitate genome mining, and these are reviewed in this Special Issue of the Journal of Industrial Microbiology and Biotechnology. In this Introductory Review, we discuss the concept of genome mining and why it is important for the revitalization of natural product discovery; what microbes show the most promise for focused genome mining; how microbial genomes can be mined; how genome mining can be leveraged with other technologies; how progress on genome mining can be accelerated; and who should fund future progress in this promising field. We direct interested readers to more focused reviews on the individual topics in this Special Issue for more detailed summaries on the current state-of-the-art. [ABSTRACT FROM AUTHOR]