Upon an invitation from Arab Bureau of Education for the Gulf States "ABEGS"; an International Conference on Biotechnology and Applied Microbiol­ ogy was held in Riyadh, Saudi Arabia, 12-15 November 1984. The Conference was sponsored by ABEGS and organized through coopera­ tion with Saudi Biological Society "SBS". ABEGS was established in 1976 with the aim of coordinating, unifying and developing all aspects of Education, Culture and Science in the Gulf States. In the field of publications, ABEGS is publishing various books, pamphlets and two scientific journals, one in Arabic and the other in English entitled: the Arab Gulf Journal of Scientific Research. This volume contains topics presented by the invited speakers and selected papers from among those submitted by participants. Selection was done on basis of some of the invited talks. Main topics of the conference were grouped into sections representing seven themes of Biotechnology and Applied Microbiology: - production of microbial proteins - utilization of microorganisms for the production of chemicals - microbial treatment and utilization of waste - continuous culture - application of biotechnology in plant science - applied microbiology and environment and - applied microbiology and biotechnology: international cooperation - tween developed and developing countries. Some of the topics in this volume present surveys of recent developments in several important areas of biotechnology and applied microbiology, while the remaining papers carry detailed research contributions.