Isolation and identification by 16S rRNA sequence analysis of plant growth-promoting azospirilla from the rhizosphere of wheat

ABSTRACT The main objective of the present study was to isolate phytohormone-producing, phosphate-solubilizing strains of Azospirillum from wheat to be used as inoculants for plant growth promotion. Five Azospirillum strains were isolated from the rhizosphere of field-grown wheat (Triticum aestivum L.), and it was confirmed by BOX-polymerase chain reaction (PCR) that the isolates were different and not re-isolates of the same strain. Sequence analysis of the PCR-amplified 16S rRNA gene indicated that four isolates showed maximum similarity to Azospirillum brasilense and one isolate showed maximum similarity to Azospirillum zeae. This is the first report indicating the presence of an A. zeae like isolate in the wheat rhizosphere in Pakistan. The bacterial isolates were characterized for their plant growth-promoting traits, phosphate solubilization, and indole-3-acetic acid (IAA) production. None of the isolates showed phosphate solubilization activity in the commonly used Pikovskaya medium. However, all strains (except AzoK4) exhibited ability to solubilize tricalcium phosphate (TCP) in modified Pikovskaya medium in which sucrose was replaced by Na-malate, as well as in TCP-supplemented Luria-Bertani (LB) medium. Organic acids, such as acetic, citric, lactic, malic, and succinic acids, were detected in culture supernatants of the tested Azospirillum strains. All strains exhibited ability to produce IAA in the growth medium, except Azospirillum sp. AzoK1. Among the strains tested, the maximum IAA production (30.49 ± 1.04 mg L-1) and phosphate solubilization (105.50 ± 4.93 mg L-1) were shown by a pure culture of Azospirillum sp. AzoK2. In pot experiments, single-strain inocula of Azospirillum sp. AzoK1 and AzoK2 improved wheat plant growth.

Citomegalovirosis cutánea en un paciente con SIDA / Cutaneous cytomegalovirus infection in an AIDS patient

Presentamos un paciente con SIDA, de sexo masculino y 43 años de edad, con una úlcera localizada en el cuerpo de pene de 6 meses de evolución. En el estudio histopatológico se observó la presencia de células con numerosas inclusiones intracitoplasmáticas irregulares y basofílicas y en las células endoteliales inclusiones intranucleares prominentes, redondeadas,rodeadas de un halo claro. Esto permitió llegar al diagnóstico de lesión ulcerosa crónica vinculable a infección por citomegalovirus. Se consideran además, en este artículo, otros métodos diagnósticos, así como la terapéutica de la entidad

Sintese de novos derivados do acido 3-fosfonopropionico / Synthesis of new derivatives of 3-phosphonopropionic acid

Foram sintetizadas tres series de derivados do acido 3-fosfonopropionico, compreendendo 22 substancias, das quais 16 ainda nao descritas na literatura. Todas as substancias foram caracterizadas por analise elementar, espectroscopia no infravermelho e espetrometria de ressonacia magnetica protonica. Os compostos obtidos foram encaminhados para ensaios experimentais na doenca de Chagas

Ensaio biologico de novos derivados do acido 3-fosfonopropionico contra o TRYPANOSOMA CRUZI / Biological assay of new derivatives of 3-phosphonopropionic acid against TRYPANOSOMA CRUZI

Diversos derivados do acido 3-fosfonopropionico foram submetidos a ensaios in vivo e in vitro, contra formas tripomastigotas da cepa Y de Trypanosoma Cruzi. Nos ensaios in vivo, realizados em camundongos previamente infectados,os derivados ensaiados se mostraram inativos, sendo que os acidos (R,S)-3-fenil-3-fosfonopropionico e (R,S)-3-fenil-3-(0,0-dietilfosfono)-propionico foram letais para alguns dos animais. Nos ensaios in vitro efetuados em cultura de tecido os compostos ensaiados foram inativos, com excecao do (R,S)-3-fenil-3-(0,0-dietilfosfono)-propionato de etila, que apresentou alguma atividade.