i suggest you to try dextrins like maltodextrin and cyclodextrin. this substances are eco-friendly and cost-effective. also provides you to use higher temperatures and shorter periods of time in drying.
In terms of inoculants more work has been done with Rhizobia than other organisms. The use of organic carriers such as peat and cocopeat are preferred for their cost and the ability to favor survival of the bacteria. In terms of materials for use under tropical conditions the use of Bacillus species are particularly adaptable because the cultures can be stimulated to produce resistant endospores. In terms of fungi Trichoderma would be of much interest they will be more storable using procedure to stimulate chlamydospore production. In inoculant production multiple screens are usually used to help assure soil adaptation. The organisms are grown in fermenters and the cultures are mixed to peat or cocopeat materials which are amended to create favorable pH. Composted materials can work very well. When the appropriate pH is maintained and the materials are used to adsorb the bacterial units or spores and dried to a proper humidity and stored under controlled temperature and packaging. For a tropical environment I would suggest using cocopeat ideally and peat amended with lime for temperate areas. In a commercial situation the products need testing and expiration date.