Cyanide, haematology and histopathology profiles of albino rats fed with 'Fufu'-based diets produced from mixed starter cultures

The cyanide, haematology and histopathology profiles of white albino rats fed with ‘fufu’-based diets were monitored. The cassava tubers were subjected into different processing operations: spontaneous-soaked traditional method (SWI), grated before spontaneously-fermented without starter culture (CWI) and those grated, blanched at 65 °C for 15 min before fermented with microorganisms isolated, purified and identified from spontaneously fermented ‘fufu’ categorized into Bacteria only (BAP), Bacteria and Yeast (BYP), Yeast only (YAP), Bacteria and Mould (BMP), Mould and Yeast (MYP) and Mould only (MAP) and were oven dried and milled. The commercial ready-to-eat ‘Fufu’ (CWF) was served as control for laboratory processed samples. Albino rats of the wister strain with four (4) rats per group were fed with 50 % of Commercial vital feed (CVF) and 50% each of the remaining nine (9) “Fufu” samples in ratio 1:1 before haematology and histopathology profile of the animals were investigated. It was found out that Samples BMP and MAP had abnormal high Neutrophil (58–60; 41–42 %) lower Lymphocyte (40–43; 58–61 %), lower Packed cell volume (46–48; 45–47 %) and higher cyanide in the blood (0.004–0.006 mg/L) with sample BMP highest white blood cell (23–24 × 10⁹/L) and sample MAP least white blood cell (6.5–6.6 × 10⁹/L) when compared with other samples which were within the acceptable recommended values for animal studied for haematology and histopathology profiles. The “fufu” samples had reduced cyanide levels ranging from 0.001 mg/L to 0.006 mg/L in the blood of the animals assayed due to the processing operations used. Therefore, combined use of bacteria isolated as starter cultures in the production of odourless “Fufu” have acceptable haematology, histopathology and reduced cyanide level which suggests the suitability in terms of safety for human consumption.

Cell-to-cell signaling in the symbiotic nitrogen-fixing bacterium Rhizobium leguminosarum: autoinduction of a stationary phase and rhizosphere-expressed genes

The Sym plasmid pRL1JI encodes functions for the formation of nitrogen-fixing pea root nodules by Rhizobium leguminosarum. Some of the nodulation genes are involved in recognition of chemical signals produced by the plant root, and others are required for production of chemical signals recognized by the plant. pRL1JI also contains a regulatory gene, rhiR, that is homologous to luxR, the transcriptional activator of luminescence genes in Vibrio fischeri. LuxR requires a signal compound, an autoinducer, for its activity. We have identified an R. leguminosarum autoinducer that, together with RhiR, is required to activate both the rhizosphere-expressed rhiABC operon and a growth-inhibiting function encoded by pRL1JI. This intercellular signal is an N-acylated homoserine lactone structurally related to the V. fischeri and other autoinducers. These findings indicate a new level of intercellular communication in root nodule formation.