Bacteria that produce lactic acid have been used for thousands of years to preserve food. Some lactic acid bacteria also produce several other mold-inhibiting substances and are therefore of special interest to agriculture and the foodstuffs industry. This is demonstrated in a dissertation by Jörgen Sjögren from the Swedish University of Agricultural Sciences, SLU. One of the bacteria strains studied has been patented and will be part of a new biological conservation preparation.
Humans have long used different micro-organisms to season and conserve foods. The Sumerians, for example, used yeast fungus to make beer 4,000 years ago. Other micro-organisms that humans have utilized for a long time are lactic acid bacteria and propionic acid bacteria. Lactic acid bacteria have been used to make cultured milk, cheese, yoghurt, and fermented sausage, and they are also put to work in silaging. Propionic acid bacteria have primarily been exploited in the production of certain large-hole cheeses, such as Swedish Grevé and Emmental.
Jörgen Sjögren has studied the fungus-inhibiting function of a number of strains of lactic acid bacteria and propionic acid bacteria in order to find strains that can be used to inhibit the growth of mold in silage, for instance. It has long been known that lactic acid bacteria and propionic acid bacteria produce the organic acids lactic acid, acetic acid, and propionic acid. All of these acids can inhibit mold fungi, but Jörgen Sögren and his associates have also seen that certain lactic acid bacteria and propionic acid bacteria moreover produce other substances (metabolites) with fungus-inhibiting properties. Twelve such substances are reported in the dissertation.
David Stephanson | alfa
Kakao in Monokultur verträgt Trockenheit besser als Kakao in Mischsystemen
18.09.2017 | Georg-August-Universität Göttingen
Ultrasound sensors make forage harvesters more reliable
28.08.2017 | Fraunhofer-Institut für Zerstörungsfreie Prüfverfahren IZFP
Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.
A warming planet
Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.
The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...
Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...
Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!
When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...
For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.
Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...
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