Quality Assurance of BIOFIX Inoculants in Kenya

1. Quality Assurance of BIOFIX Inoculants in Kenya N.K. Karanja, S. Kisamuli, T. Wafula and P.L. Woomer UoN MIRCEN, MEA Fertilizers Ltd. and N2Africa Project Background: Legume inoculants are produced by MEA Fertilizer Ltd. under the trade name BIOFIX. While no industry standards have yet to be established in Kenya, it is nonetheless important that an independent quality assessment be conducted. This service is conducted by the University of Nairobi MIRCEN Laboratory. Product targets are at least 10^9 rhizobia per gram of inoculant and no more than 10^7 contaminants. Approach: Inoculants are submitted to MIRCEN from the BIOFIX factory in Nakuru and assessed on CR YMA in triplicate using the drop plate method, with the 10-5 to 10-7 dilutions plated. Results are entered into a spreadsheet utility to calculate the inoculant population, total contaminants and their respective CVs. Quality assessment reporting: Results are reported for specific batches with duplicate samples per batch (see utility output below). Results are summarized into a “sample and batch report” (below right). These results are then relayed to the MIRCEN Director and MEA’s Factory Supervisor. Each batch consists of about 1000 packets of inoculant, resulting in 0.2% quality assurance sub-sampling. Challenges: The reporting time is currently too late to intercept inferior samples from the manufacturer’s inventory. Contaminants continue to exceed targets. Some inoculants appear to contain mixed cultures (right). These shortcomings are currently being addressed by the factory and laboratory. For more information contact Prof. Karanja by emailing nancy.karanja@cgiar.org