Anaerobic Fish Spoilage by Bacteria II. Kinetics of Bacterial Growth and Substrate Conversions in Herring Extracts

Abstract

The time course of the conversions of chemical components in herring extracts during anaerobic growth of Proteus sp., str. NTHC 153, Aeromonas sp., str. NTHC 154, and Enterobacter sp., str. NTHC 151 (Strøm & Larsen 1979) has been studied. When the Proteus sp. or the Aeromonas sp. were inoculated into the herring extracts and incubated at 15°C under anaerobic conditions, the sugar components (i.e. mainly ribose, free and bound) were the first substrates utilized. These compounds were converted to acetate and CO2 by the use of trimethylamine oxide (TMAO) as an external hydrogen acceptor. Growth of bacteria ceased when all TMAO was reduced to trimethylamine (TMA). By adding an extra amount of TMAO to the herring extracts an increased growth of the Proteus sp. and the Aeromonas sp. ensued. The increased growth occurred concomitantly with a further conversion of TMAO to TMA and of lactate to acetate and CO2. The Enterobacter sp., which did not utilize lactate, did not give an increased growth in herring extracts enriched with TMAO.

An inductively coupled passive tag for remote basic volatile sensing

“…During food spoilage, the growth of yeasts and microbes results in production of organic acids, and volatile acidic and basic gases. Therefore, increase of acidic and basic volatiles inside the food packages serves as an indicator for food spoilage [2], [4], [5]. For example, volatile amines such as trimethylamine (N(CH 3 ) 3 ), dimethylamine ((CH 3 ) 2 NH) and ammonia (NH 3 ) are products of microbial degradation of fish and are collectively known as total volatile basic nitrogen (TVBN).…”

Monitoring acidic and basic volatile concentration using a pH-electrode based wireless passive sensor

“…During food spoilage, the growth of yeasts and microbes results in production of organic acids, and acidic and basic volatiles. Monitoring the increase of these volatiles inside food packages can serve as an indicator for food spoilage [2,[5][6][7]. For example, microbial degradation of fish produces volatile amines such as trimethylamine (N(CH 3 ) 3 ), dimethylamine ((CH 3 ) 2 NH) and ammonia (NH 3 ).…”