Credit securitization and credit derivatives : financial instruments and the credit risk management of middle market commercial loan portfolios

Banks increasingly recognize the need to measure and manage the credit risk of their loans on a portfolio basis. We address the subportfolio "middle market". Due to their specific lending policy for this market segment it is an important task for banks to systematically identify regional and industrial credit concentrations and reduce the detected concentrations through diversification. In recent years, the development of markets for credit securitization and credit derivatives has provided new credit risk management tools. However, in the addressed market segment adverse selection and moral hazard problems are quite severe. A potential successful application of credit securitization and credit derivatives for managing credit risk of middle market commercial loan portfolios depends on the development of incentive-compatible structures which solve or at least mitigate the adverse selection and moral hazard problems. In this paper we identify a number of general requirements and describe two possible solution concepts

Empirical analysis of credit relationships in small firms financing : sampling design and descriptive statistics

Despite the relevance of credit financing for the profit and risk situation of commercial banks only little empirical evidence on the initial credit decision and monitoring process exists due to the lack of appropriate data on bank debt financing. The present paper provides a systematic overview of a data set generated during the Center for Financial Studies research project on "Credit Management" which was designed to fill this empirical void. The data set contains a broad list of variables taken from the credit files of five major German banks. It is a random sample drawn from all customers which have engaged in some form of borrowing from the banks in question between January 1992 and January 1997 and which meet a number of selection criteria. The sampling design and data collection procedure are discussed in detail. Additionally, the project's research agenda is described and some general descriptive statistics of the firms in our sample are provided

Verminderung von Verhaltensstörungen beim Schwein: Evaluierung geeigneter Möglichkeiten zur Verminderung des Auftretens von Verhaltensstörungen beim Schwein

Zu der Verhaltensstörung ‘Kannibalismus’ bei Schweinen kommt es, sobald ein wichtiger, das Wohlbefinden der Schweine beeinflussender Faktor fehlt. Anhand der Untersuchung von Tätertieren wurden Haltungs- und Fütterungsfaktoren bewertet. Das Risiko für Verhaltensstörungen kann statistisch gesichert mit dem Geschlecht, der Gruppengröße, der Besatzdichte, der Sortierung und der Beschäftigung der Tiere in Verbindung gebracht werden. Grundvoraussetzung für den Kupierverzicht sind gesunde Bestände. Die Ergebnisse dienen der Weiterentwicklung der Haltungstechnik, bewerten aber auch die möglichen Folgen einer vorzeitigen Umsetzung des Kupierverbotes

Corynebacterium glutamicum as a platform strain for the production of a broad variety of terpenoids

Corynebacterium glutamicum is a natural carotenoid producing bacterium used in the million-ton-scale amino acid biotechnology that has been engineered for isoprenoid production1. The native membrane-bound carotenoid decaprenoxanthin is a rare C50 carotenoid. Volatile terpenoids such as valencene2 and patchoulol3 could be produced upon deletion of the first step of the specific carotenoid pathway and heterologous expression of the FPP synthase gene ispA from E. coli and terpene synthases from plant origin. However, these strains produced a yet unidentified carotenoid and only when all carotenoid biosynthetic genes were deleted, a colorless strain resulted. Expressing a codon optimized ADS from Artemisia annua in the white strain, amorphadiene, the volatile precursor for artemisinin was produced. For production of volatile terpenoids a dodecane overlay was used, a condition in which C. glutamicum benefits from its robust myco-membrane. Recently, we showed production of membrane-bound carotenoids with different length and/or cyclization status: bicyclic C50 sarcinaxanthin4, bicyclic C40 astaxanthin5, the linear lycopene6 and the linear C50 bisanhydrobacterioruberin7. This indicated that the C. glutamicum myco-membrane accepts these linear and bicyclic carotenoids. Please click Additional Files below to see the full abstract

Overexpression of the primary sigma factor gene sigA improved carotenoid production by Corynebacterium glutamicum: application to production of beta-carotene and the non-native linear C50 carotenoid bisanhydrobacterioruberin

Taniguchi H, Henke NA, Heider S, Wendisch VF. Overexpression of the primary sigma factor gene sigA improved carotenoid production by Corynebacterium glutamicum: application to production of beta-carotene and the non-native linear C50 carotenoid bisanhydrobacterioruberin. Metabolic Engineering Communications. 2017;4:1-11.Corynebacterium glutamicum shows yellow pigmentation due to biosynthesis of the C50 carotenoid decaprenoxanthin and its glycosides. This bacterium has been engineered for production of various non-native cyclic C40 and C50 carotenoids such as β-carotene, astaxanthin or sarcinaxanthin. In this study, the effect of modulating gene expression more broadly by overexpression of sigma factor genes on carotenoid production by C. glutamicum was characterized. Overexpression of the primary sigma factor gene sigA improved lycopene production by recombinant C. glutamicum up to 8-fold. In C. glutamicum wild type, overexpression of sigA led to 2-fold increased accumulation of the native carotenoid decaprenoxanthin in the stationary growth phase. Under these conditions, genes related to thiamine synthesis and aromatic compound degradation showed increased RNA levels and addition of thiamine and the aromatic iron chelator protocatechuic acid to the culture medium enhanced carotenoid production when sigA was overexpressed. Deletion of the gene for the alternative sigma factor SigB, which is expected to replace SigA in RNA polymerase holoenzymes during transition to the stationary growth phase, also increased carotenoid production. The strategy of sigA overexpression could be successfully transferred to production of the non-native carotenoids β-carotene and bisanhydrobacterioruberin (BABR). Production of the latter is the first demonstration that C. glutamicum may accumulate a non-native linear C50 carotenoid instead of the native cyclic C50 carotenoid decaprenoxanthin

Production of the marine carotenoid astaxanthin by metabolically engineered Corynebacterium glutamicum

Henke NA, Heider S, Peters-Wendisch P, Wendisch VF. Production of the marine carotenoid astaxanthin by metabolically engineered Corynebacterium glutamicum. Marine Drugs. 2016;14(7): 124.Astaxanthin, a red C40 carotenoid, is one of the most abundant marine carotenoids. It is currently used as a food and feed additive in a hundred-ton scale and is furthermore an attractive component for pharmaceutical and cosmetic applications with antioxidant activities. Corynebacterium glutamicum, which naturally synthesizes the yellow C50 carotenoid decaprenoxanthin, is an industrially relevant microorganism used in the million-ton amino acid production. In this work, engineering of a genome-reduced C. glutamicum with optimized precursor supply for astaxanthin production is described. This involved expression of heterologous genes encoding for lycopene cyclase CrtY, β-carotene ketolase CrtW, and hydroxylase CrtZ. For balanced expression of crtW and crtZ their translation initiation rates were varied in a systematic approach using different ribosome binding sites, spacing, and translational start codons. Furthermore, β-carotene ketolases and hydroxylases from different marine bacteria were tested with regard to efficient astaxanthin production in C. glutamicum. In shaking flasks, the C. glutamicum strains developed here overproduced astaxanthin with volumetric productivities up to 0.4 mg·L−1·h−1 which are competitive with current algae-based production. Since C. glutamicum can grow to high cell densities of up to 100 g cell dry weight (CDW)·L−1, the recombinant strains developed here are a starting point for astaxanthin production by C. glutamicum

Isoprenoid pyrophosphate-dependent transcriptional regulation of carotenogenesis in Corynebacterium glutamicum

Henke NA, Heider S, Hannibal S, Wendisch VF, Peters-Wendisch P. Isoprenoid pyrophosphate-dependent transcriptional regulation of carotenogenesis in Corynebacterium glutamicum. Frontiers in Microbiology. 2017;8: 633.Corynebacterium glutamicum is a natural producer of the C50 carotenoid decaprenoxanthin. The crtEcg0722crtBIYEb operon comprises most of its genes for terpenoid biosynthesis. The MarR-type regulator encoded upstream and in divergent orientation of the carotenoid biosynthesis operon has not yet been characterized. This regulator, named CrtR in this study, is encoded in many actinobacterial genomes co-occurring with terpenoid biosynthesis genes. CrtR was shown to repress the crt operon of C. glutamicum since DNA microarray experiments revealed that transcript levels of crt operon genes were increased 10 to 70-fold in its absence. Transcriptional fusions of a promoter-less gfp gene with the crt operon and crtR promoters confirmed that CrtR represses its own gene and the crt operon. Gel mobility shift assays with purified His-tagged CrtR showed that CrtR binds to a region overlapping with the −10 and −35 promoter sequences of the crt operon. Isoprenoid pyrophosphates interfered with binding of CrtR to its target DNA, a so far unknown mechanism for regulation of carotenogenesis. The molecular details of protein-ligand interactions remain to be studied. Decaprenoxanthin synthesis by C. glutamicum wild type was enhanced 10 to 30-fold upon deletion of crtR and was decreased 5 to 6-fold as result of crtR overexpression. Moreover, deletion of crtR was shown as metabolic engineering strategy to improve production of native and non-native carotenoids including lycopene, β-carotene, C.p. 450 and sarcinaxanthin

Development of single-tube nested real-time PCR assays with long internally quenched probes for detection of norovirus genogroup II

Publisher Copyright: © 2016, Eaton Publishing Company. All rights reserved.The high sequence variation of RNA viruses necessitates use of degenerate primers and probes or multiple primers and probes in molecular diagnostic assays. We showed previously that PCR amplification in two rounds, first with long target-specific primers and then with short generic primers, followed by detection using long probes, can tolerate sequence variation. Here we demonstrate that long primers and probes of up to 56 nucleotides can also be applied in real-time PCR for the detection of norovirus genogroup II with improved sensitivity. Probe design (method of incorporating quenchers, use of Zen internal quencher or traditional quenchers) greatly affects the sensitivity of the real-time PCR assays.Peer reviewe