Cometabolic biodegradation of quizalofop-p-ethyl by Methylobacterium populi YC-XJ1 and identification of QPEH1 esterase

BACKGROUND: Quizalofop-p-ethyl (QPE), a unitary R configuration aromatic oxyphenoxypropionic acid ester (AOPP) herbicide, was widely used and had led to detrimental environmental effects. For finding the QPEdegrading bacteria and promoting the biodegradation of QPE, a series of studies were carried out. RESULTS: A QPE-degrading bacterial strain YC-XJ1 was isolated from desert soil and identified as Methylobacterium populi, which could degrade QPE with methanol by cometabolism. Ninety-seven percent of QPE (50 mg/L) could be degraded within 72 h under optimum biodegradation condition of 35°C and pH 8.0. The maximum degradation rate of QPE was 1.4 mg/L/h, and the strain YC-XJ1 exhibited some certain salinity tolerance. Two novel metabolites, 2-hydroxy-6-chloroquinoxaline and quinoxaline, were found by high-performance liquid chromatography/mass spectroscopy analysis. The metabolic pathway of QPE was predicted. The catalytic efficiency of strain YC-XJ1 toward different AOPPs herbicides in descending order was as follows: haloxyfop-pmethyl ≈ diclofop-methyl ≈ fluazifop-p-butyl N clodinafop-propargyl N cyhalofop-butyl N quizalofop-p-ethyl N fenoxaprop-p-ethyl N propaquizafop N quizalofop-p-tefuryl. The genome of strain YC-XJ1 was sequenced using a combination of PacBio RS II and Illumina platforms. According to the annotation result, one α/ß hydrolase gene was selected and named qpeh1, for which QPE-degrading function has obtained validation. Based on the phylogenetic analysis and multiple sequence alignment with other QPE-degrading esterases reported previously, the QPEH1 was clustered with esterase family V. CONCLUSION: M. populi YC-XJ1 could degrade QPE with a novel pathway, and the qpeh1 gene was identified as one of QPE-degrading esterase gene.

Artemisinin from minor to major ingredient in Artemisia annua cultivated in Egypt.

Artemisia annua is currently the only source for the commercial pharmaceutical production of artemisinin as neither its chemical synthesis nor its in vitro production is economically feasible. However, the very low amount of artemisinin in Artemisia annua L., (0.01-0.6%) of dry weight has made artemisinin-based drugs remains expensive and is hardly available on a global scale. Limitations in the supply of this promising and most potent antimalarial compound makes the cultivation of this plant is still the only valid source to satisfy the high demands and the vast need of artemisinin at a reduced acceptable market price for most patients. In this paper we attempted to increase the cultivating area of this important plant by cultivating A.annua seeds for the first time in the western desert of Egypt to improve its agricultural yields in order to ensure a steady global supply of artemisinin and to study the environmental impact of the cultivation area on the amount of artemisinin production. The high artemisinin concentration reported in this study (4.85-4.90%) of dry weight has identified the Egyptian desert for the first time as a new promising cultivating area for pharmaceutical production of artemisinin. A very simple method was developed using liquid chromatography tandem mass spectrometry (LCMS/ MS) for the quantification of artemisinin in both plant material and pure samples.

Artemisinin from minor to major ingredient in Artemisia annua cultivated in Egypt.

Artemisia annua is currently the only source for the commercial pharmaceutical production of artemisinin as neither its chemical synthesis nor its in vitro production is economically feasible. However, the very low amount of artemisinin in Artemisia annua L., (0.01-0.6%) of dry weight has made artemisinin-based drugs remains expensive and is hardly available on a global scale. Limitations in the supply of this promising and most potent antimalarial compound makes the cultivation of this plant is still the only valid source to satisfy the high demands and the vast need of artemisinin at a reduced acceptable market price for most patients. In this paper we attempted to increase the cultivating area of this important plant by cultivating A.annua seeds for the first time in the western desert of Egypt to improve its agricultural yields in order to ensure a steady global supply of artemisinin and to study the environmental impact of the cultivation area on the amount of artemisinin production. The high artemisinin concentration reported in this study (4.85-4.90%) of dry weight has identified the Egyptian desert for the first time as a new promising cultivating area for pharmaceutical production of artemisinin. A very simple method was developed using liquid chromatography tandem mass spectrometry (LCMS/ MS) for the quantification of artemisinin in both plant material and pure samples.

Reproducción y ultraestructura del huevo y larva de primer estadio de Gyriosomus kingi (Coleoptera: Tenebrionidae) del desierto de Atacama

Reproduction and ultrastructure of egg and first instar larvae of Gyriosomus kingi (Coleoptera: Tenebrionidae) from the desert of Atacama. Gyriosomus is an important Chilean genus of Tenebrionidae, inhabiting the coastal desert of this country. in this environment, the Gyriosomus-species are both eremic and endemic components of the epigean entomofauna. Despite the ecological importance of these species in the Chilean desert, there is a lack of knowledge on the preimaginal stages of them. in this paper we describe the egg and first instar larval morphology of G. kingi Reed, 1873, along with some bionomic aspects of the female. The eggs and larva were obtained from couples kept under laboratory conditions, after being captured during the spring of year 2002, in coastal sites of National Park Llanos de Challe, located in the southern border of the Atacama Desert (28°01’S, 71°03’W). The first third of the chorion presents subhexagonal cells lacking aeropyles. The larvae is oligopod and elongated. its cephalic capsule is strongly chitinized with the prothoracic legs longer and thicker than the rest. According laboratory observations, each egg-laying includes seven to ten eggs each time, with a maximum of six egg-laying per female. The eggs are buried into the soil, covered by a mucilaginous layer which creates a clay-sandy film attached to the chorion. Rev. Biol. Trop. 55 (2): 637-644. Epub 2007 June, 29.

Gyriosomus es un importante género chileno de Tenebrionidae, habitante del desierto costero del país. En este ambiente, las especies de Gyriosomus son un componente erémico y endémico de la entomofauna epígea. A pesar de la importancia ecológica que estas especies tienen en el desierto chileno, poco se conoce respecto de la morfología de los estados preimaginales. En este trabajo se describe la morfología del huevo y de la larva de primer estadio de G. kingi Reed, 1873, y se entregan algunos antecedentes acerca de la bionomía de la hembra. Los huevos y las larvas fueron obtenidos a partir de parejas mantenidas en condiciones de laboratorio. Los adultos fueron capturados durante la primavera del año 2002, en sitios costeros del Parque Nacional Llanos de Challe, localizado en la frontera sur del Desierto de Atacama (28°01’S; 71°03’W). El primer tercio del corión del huevo presenta celdas subhexagonales sin aeropilas. La larva es oligópoda y elongada. Su cápsula cefálica está fuertemente quitinizada y sus patas protorácicas son más largas y más gruesas que las restantes. Según observaciones de laboratorio, cada ovipostura incluye de siete a diez huevos cada vez, con un máximo de seis oviposturas por hembra. Los huevos son enterrados en el suelo, recubiertos con un mucílago que genera una película de arena-arcilla adherida al corión.