Activities of the USP Microbiology Subcommittee of Revision during the 1995-2000 revision cycle.

This article is a comprehensive review of the published activities of the Microbiology Subcommittee of the USP Committee of Revision for the 1995-2000 revision cycle. The activities of this revision cycle were designed to position USP activities in microbiology that will be useful as technology advances. In addition to reviewing the changes accomplished, this article discusses the rationale for many of the changes and some background information on new initiatives underway. Where appropriate, changes in the USP that did not fall under the direct purview of the MCB Subcommittee but of interest to the microbiology community are also discussed.

Pharmacopeial harmonization in biotechnology.

There has been progress in the pharmacopeial harmonization initiative among the United States Pharmacopeia (USP), the European Pharmacopoeia and the Japanese Pharmacopoeia. Monographs on excipients and on biotechnology-derived products, as well as for General Chapters are progressing through the various stages of the harmonization process. An additional initiative, Concordance of Foreign Pharmacopeial Tests and Assays has been proposed by the USP.

Survival of Salmonella anatum heated in various media.

Survival of Salmonella anatum heated at 55 C for 35 min was determined in solutions of various chemical constituents of foods including salts, carbohydrates, amino acids, peptides, nucleic acids, gums, and stabilizers and compared with survival in 0.1 m phosphate buffer (pH 7.0). Commercially sterilized whole milk gave the most protection against heat. Trypticase Soy Broth, various peptide mixtures, and some amino acids gave substantial protection. Results with carbohydrates were variable, with mannitol, sucrose, and rhamnose providing substantial protection and glucose decreasing heat resistance. A few other substances, cysteine, glutathione, and sodium citrate, also decreased heat resistance. Pure proteins had little effect. Results show that water activity is of little significance under the test conditions. Protection from heat probably results from complexing of substances with heat-sensitive proteins in the cells. Autoclaved milk should not be considered equivalent to raw milk for studies of survival of bacteria during heating.

Antimicrobial action of some citrus fruit oils on selected food-borne bacteria.

The antimicrobial properties of essential oils, terpineol, and orange oil, in particular, varied according to the type of bacteria tested. Terpineol and other terpeneless fractions of citrus oils appeared to have greater inhibitory effect on food-borne bacteria than the other citrus oils or derivatives. Gram-positive bacteria were, in general, more sensitive to essential oils than gram-negative bacteria. Terpineol extended the shelf life of commercially pasteurized skim milk, low-fat milk, and whole milk for more than 56 days at 4 C. Orange oil extended the shelf life of skim milk and low-fat milk for the same period.