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Group B streptococcus (GBS) is a leading cause of neonatal sepsis and meningitis. We determined the distribution of serotypes and surface protein encoding genes of GBS strains from pregnant and non-pregnant women in Egypt. Vaginal swabs from 364 women were screened by culture and 100 (27.4%) yielded GBS. Serotype V was the most predominant (33%), followed by serotypes II (17%), III (15%), Ia (14%), VI (12%), Ib (8%) and IV (1%). The most common surface protein genes were epsilon (27%), alp3 (26%), bca (18%), rib (16%) and alp2 (10%). Two isolates were negative for surface protein genes. The distribution of serotypes and surface proteins was similar to reports from other parts of the world but the relatively high frequency of serotype VI was a notable feature of the strains from women in Egypt.

Auxotrophic mutants of the actinomycete Amycolatopsis methanolica requiring L-Phe or L-Tyr were isolated and identified as strains lacking prephenate dehydratase (strain GH71) or arogenate dehydrogenase (strain GH70), respectively. A. methanolica thus employs single pathways only for the biosynthesis of these aromatic amino acids. Anion-exchange chromatography of extracts revealed two peaks with Phe as well as Tyr aminotransferase (AT) activity (Phe/Tyr ATI and Phe/Tyr ATII) and three peaks with prephenate AT activity (Ppa ATI to Ppa ATIII). Phe/Tyr ATI and Ppa ATI coeluted and appear to function as the A. methanolica branchedchain amino acid AT. Ppa ATII probably functions as the aspartate AT. Mutant studies showed that Phe/Tyr ATII is the dominant AT in L-Phe biosynthesis and in L-Tyr catabolism but not in L-Tyr biosynthesis. Biochemical studies showed that Ppa ATIII is highly specific for prephenate and provided evidence that Ppa ATIII is the dominant AT in L-Tyr biosynthesis.

Alanine aminotransferase (EC 2.6.1.2) was obtained from the fungus Leptosphaeria michotii (West) Sacc, and enriched 714‐fold by a 5‐step purification procedure as a dimer of Mr 110000, associated with a polypeptide of Mr 25000. Its isoelectric point was 5.25. The enzyme was active from pH 3.5 to 9.5 with a maximum at pH 7.5. Its specific activity was 6000 nkat (mg protein)−1; the Km was 6.85 mM for L‐alanine and 0.2 mM for 2‐oxoglutarate. The enzyme did not show any detectable activity in the presence of L‐aspartate, cysteine sulfinate, α‐aminobutyrate or cyclic amino acids as substrates. It did not express alanine:glyoxylate aminotransferase activity. Alanine aminotransferase in L. michotii has previously been shown to have an activity rhythm in constant temperature and darkness. The enzyme level was quantified along the activity rhythm by enzyme‐linked immunosorbent assay (ELISA), using a monospecific polyclonal antibody against the purified enzyme. The cyclic variations of alanine aminotransferase activity were correlated with cyclic variations in the enzyme level.

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