Definition of "inoculum" [in•oc•u•lum]

• The material used in an inoculation. Also called inoculant. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "Plants currently restricted to south-facing slopes and warm springs (to some extent analogues of future warmer habitats and hot spots of biodiversity) north of their main distribution areas are likely to provide an "inoculum" for rapid colonization of surrounding habitats when climate becomes warmer, although they themselves are likely to be displaced from their current niches by less diverse shrub – thicket communities."
• "The researchers took an inoculum from the hypersaline, alkaline Mono lake and grew it in serial dilutions so that the medium contained progressively increasing amounts of arsenic (As) substituting for phosphorus (P)."
• "Tighten the jar covers and shake well to disperse the inoculum throughout the broth."