EFFECT OF AW OF MEAT-PRODUCTS ON GROWTH OF RADIATION RESISTANT MORAXELLA-ACINETOBACTER

The growth response of radiation resistant Moraxella‐Acinetobacter (M‐A) was monitored relative to the a, of meat and various experimental media. Representative isolates, although obtained from beef, did not grow in ground beef, ground chicken meat, OR fresh beef exudate unless the aw was raised through water addition. Data from a psychrometric thermocouple of the Spanner‐Peltier design showed that aw levels approaching and lower than 0.99 were inhibitory to the growth of M‐A. No growth occurred in standard laboratory media when the aw was lowered to that approximating meat. Comparable lowering of aw in experimental media systems by additions of sodium hexametaphosphate, sodium chloride, yeast extract, or dehydrated m‐Plate Count Broth (PCB) gave similar results. Growth of M‐A occurred without added water in chicken exudate, on the surface of chicken wings, and on exudate saturated paper removed from commercially packaged chicken trays. M‐A growth in PCB with added ground beef was further indication that the M‐A's inability to grow was not due to an inhibitor in the meat. Copyright © 1979, Wiley Blackwell. All rights reserved