Photorhabdus luminescens is a symbiont of nematodes and a broad-spectrum insect pathogen. The complete genome sequence of strain TT01 is 5,688,987 base pairs (bp) long and contains 4,839 predicted protein-coding genes. Strikingly, it encodes a large number of adhesins, toxins, hemolysins, proteases and lipases, and contains a wide array of antibiotic synthesizing genes. These proteins are likely to play a role in the elimination of competitors, host colonization, invasion and bioconversion of the insect cadaver, making P. luminescens a promising model for the study of symbiosis and host-pathogen interactions. Comparison with the genomes of related bacteria reveals the acquisition of virulence factors by extensive horizontal transfer and provides clues about the evolution of an insect pathogen. Moreover, newly identified insecticidal proteins may be effective alternatives for the control of insect pests.

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The genome sequence of the entomopathogenic bacterium Photorhabdus luminescens

Phthalates are synthesized in massive amounts to produce various plastics and have become widespread in environments following their release as a result of extensive usage and production. This has been of an environmental concern because phthalates are hepatotoxic, teratogenic, and carcinogenic by nature. Numerous studies indicated that phthalates can be degraded by bacteria and fungi under aerobic, anoxic, and anaerobic conditions. This paper gives a review on the biodegradation of phthalates and includes the following aspects: (1) the relationship between the chemical structure of phthalates and their biodegradability, (2) the biodegradation of phthalates by pure/mixed cultures, (3) the biodegradation of phthalates under various environments, and (4) the biodegradation pathways of phthalates.

Phthalates biodegradation in the environment

Although they are less abundant than their alpha-analogues, beta-amino acids occur in nature both in free form and bound to peptides. Oligomers composed exclusively of beta-amino acids (so-called beta-peptides) might be the most thoroughly investigated peptidomimetics. Beside the facts that they are stable to metabolism, exhibit slow microbial degradation, and are inherently stable to proteases and peptidases, they fold into well-ordered secondary structures consisting of helices, turns, and sheets. In this respect, the most intriguing effects have been observed when beta2-amino acids are present in the beta-peptide backbone. This review gives an overview of the occurrence and importance of beta2-amino acids in nature, placing emphasis on the metabolic pathways of beta-aminoisobutyric acid (beta-Aib) and the appearance of beta2-amino acids as secondary metabolites or as components of more complex natural products, such as peptides, depsipeptides, lactones, and alkaloids. In addition, a compilation of the syntheses of both achiral and chiral beta2-amino acids is presented. While there are numerous routes to achiral beta2-amino acids, their EPC synthesis is currently the subject of many investigations. These include the diastereoselective alkylation and Mannich-type reactions of cyclic- or acyclic beta-homoglycine derivatives containing chiral auxiliaries, the Curtius degradation, the employment of transition-metal catalyzed reactions such as enantioselective hydrogenations, reductions, C-H insertions, and Michael-type additions, and the resolution of rac. beta2-amino acids, as well as several miscellaneous methods. In the last part of the review, the importance of beta2-amino acids in the formation of beta-peptide secondary structures is discussed.

Beta2-amino acids-syntheses, occurrence in natural products, and components of beta-peptides1,2.

Little research has been conducted on the occurrence of pharmaceuticals and personal care products (PPCPs) in the marine environment despite being increasingly impacted by these contaminants. This article reviews data on the occurrence of PPCPs in seawater, sediment, and organisms in the marine environment. Data pertaining to 196 pharmaceuticals and 37 personal care products reported from more than 50 marine sites are analyzed while taking sampling strategies and analytical methods into account. Particular attention is focused on the most frequently detected substances at highest concentrations. A snapshot of the most impacted marine sites is provided by comparing the highest concentrations reported for quantified substances. The present review reveals that: (i) PPCPs are widespread in seawater, particularly at sites impacted by anthropogenic activities, and (ii) the most frequently investigated and detected molecules in seawater and sediments are antibiotics, such as erythromycin. Moreover, this review points out other PPCPs of concern, such as ultraviolet filters, and underlines the scarcity of data on those substances despite recent evidence on their occurrence in marine organisms. The exposure of marine organisms in regard to these insufficient data is discussed.

https://hal.archives-ouvertes.fr/hal-02086817/document

Occurrence of PPCPs in the marine environment: a review

An overview of quinazolines: Pharmacological significance and recent developments.

6-Phenyl analogs of toxoflavin (1-methyl-6-phenylpyrimido[5,4-e]-1,2,4-triazine-5,7(1H,6H)-diones ) (7a--f) and their 4-oxides (8a-f) were synthesized by nitrosative or nitrative cyclization of the aldehyde hydrazones (6a-f) of 6-(1-methylhydrazino)-3-phenyluracil (5). Both sets of compounds, 7a-f and 8a-f, gave the corresponding 1-demethyl derivatives (10a-f) upon treatment with nucleophiles such as dimethylformamide (DMF) and acetic acid under heating. The activities of toxoflavins (1a-e), toxoflavin 4-oxides (3a-e) and their 6-phenyl analogs (7a-f and 8a-f) against a variety of bacterial and fungal strains were examined. Most of the compounds showed strong inhibitory activities against gram-positive bacteria. Among the compounds, 1c, 1d, 1e, and 3c exhibited the strongest inhibitions of Micrococcus lutea (0.5 micrograms/ml minimal growth-inhibitory concentration) and Staphylococcus aureus 4R (1 microgram/ml), as well as Bacillus subtilis and Staphylococcus aureus (1-2 micrograms/ml). Most of the compounds had strong antifungal activity (2-100 micrograms/ml minimal growth-inhibitory concentration) against Candida albicans and Saccharomyces cerevisiae.

Syntheses of 3-substituted 1-methyl-6-phenylpyrimido[5,4-e]-1,2,4-triazine-5,7(1H,6H)-diones (6-phenyl analogs of toxoflavin) and their 4-oxides, and evaluation of antimicrobial activity of toxoflavins and their analogs.

Topostatin is a new topoisomerase inhibitor isolated from the culture filtrate of Thermomonospora alba strain No. 1520. The inhibitor inhibits topoisomerases I and II, and it has neither ability to stabilize the cleavable complex nor ability to intercalate into DNA strands. The molecular formula of topostatin was determined as C 36 H 58 N 4 O 11 S based on the FAB-MS analyses, and the structure was elucidated to be a novel 14-membered ring containing peptide and terpenoid by various NMR spectroscopies.

Topostatin, a Novel Inhibitor of Topoisomerases I and II Produced by Thermomonospora alba Strain No. 1520 II. Physico-chemical Properties and Structure Elucidation

Two pure cultures (strains No. A-11 and A-12) from soil sample capable of utilizing aniline as the sole source of nitrogen and energy were regarded as Achromobacter sp and Pseudomonas sp, respectively. Degradation patterns of aniline and aniline derivatives were observed on the high-performance liquid chromatogram (HPLC) of the culture filtrate of both strains and growth of both strains were measured as protein by the Kennedy and Fewson method. The growth yield of both strains were about 46.3g and 47.4g of protein per mole of nitrogen source of aniline and were similar to those in the case of NH4Cl as a nitrogen source. Biodegradation of aniline was achieved (200 mg/l) in less than 3 and 4 days using strains No. A-11 and strain No. A-12, respectively. The strain No. A-11 degraded aniline more rapidly than strain No. A-12.

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Biodegradation of Endocrine-Disrupting Chemical Aniline by Microorganisms

A new antiherpetic agent, AH-1763 Ha, was isolated from the culture broth of strain No. 1763 identified as Streptomyces cyaneus. It was purified through column chromatographies of Diaion HP-10 and silica gel. The structure was determined to be ll-hydroxy-5-methyl-2-(2-hydroxy-lmethylpropyl)-4H-anthraceno[1, 2-b]pyran-4, 7, 12-trione by several spectroscopic experiments, that is a new antibiotic belonging to pluramycin-group.

A new antiherpetic agent, AH-1763 IIa, produced by Streptomyces cyaneus strain no. 1763.

A new antiherpetic agent, AH-758, was isolated from the culture broth of Streptomyces sp. strain No. 758. The structure was determined by NMR spectral analyses to be a new antibiotic belonging to bafilomycin group containing (5-oxo-2-pyrrolin-2-yl) methyl fumarate in its C-21.

Yutaka Kido

Papers

Syntheses of 3-substituted 1-methyl-6-phenylpyrimido[5,4-e]-1,2,4-triazine-5,7(1H,6H)-diones (6-phenyl analogs of toxoflavin) and their 4-oxides, and evaluation of antimicrobial activity of toxoflavins and their analogs.

Topostatin, a Novel Inhibitor of Topoisomerases I and II Produced by Thermomonospora alba Strain No. 1520 II. Physico-chemical Properties and Structure Elucidation

Biodegradation of Endocrine-Disrupting Chemical Aniline by Microorganisms

A new antiherpetic agent, AH-1763 IIa, produced by Streptomyces cyaneus strain no. 1763.

A new antiherpetic agent produced by Streptomyces sp. strain no. 758.