Yoshikatsu Murooka

Traditional healthful fermented products of Japan.

A variety of fermentation products, such as foods containing probiotic bacteria, black rice vinegar (kurosu), soy sauce (shoyu), soybean-barley paste (miso), natto and tempeh, are sold in food stores in Japan. These fermented food products are produced by traditional methods that exploit mixed cultures of various non-toxic microorganisms. These microorganisms include lactic acid bacteria, acetic acid bacteria, sake yeast, koji molds and natto bacteria. Many traditional fermented foods have been studied and their effects on metabolism and/or immune system have been demonstrated in animal and/or human cells. This review summarizes the scientific basis for the effects of these traditional food products, which are currently produced commercially in Japan.

Vinegars Through the Ages

The word vinegar has been in use in the English language since the 14th century, when it arrived in the British Isles from the French vinaigre, a word that simply means ‘sour wine’, and that came in turn from the Latin vinum acre, ‘sour wine’ or, more commonly, vinum acetum, ‘wine vinegar’.

Prophylactic effect of Lactobacillus oral vaccine expressing a Japanese cedar pollen allergen

Lactic acid bacteria (LAB) represent an attractive delivery vehicle for oral allergy vaccine because of their safety as a food microorganism as well as their potent adjuvant activity triggering anti-allergic immune response. Here, we report the generation of recombinant LAB expressing a major Japanese cedar pollen allergen Cry j 1 (Cry j 1-LAB), and their prophylactic effect in vivo. To facilitate heterologous expression, the codon usage in the Cry j 1 gene was optimized for the host LAB strain Lactobacillus plantarum by the recursive PCR-based exhaustive site-directed mutagenesis. Use of the codon-optimized Cry j 1 cDNA and a lactate dehydrogenase gene fusion system led to a successful production of recombinant Cry j 1 in L. plantarum NCL21. We also found that oral vaccination with the Cry j 1-LAB suppressed allergen-specific IgE response and nasal symptoms in a murine model of cedar pollinosis.

Bioremediation of heavy metals through symbiosis between leguminous plant and rhizobium with engineered metallothionein and phytochelatin synthase genes

We developed a novel bioremediation system, symbiotic engineering, based on the symbiosis between leguminous plant, Astragalus sinicus and the recombinant rhizobium, Mesorhizobium huakuii subsp. rengei B3, by over expressing a synthetic tetrameric metallothionein gene (MTL4) and cDNA encoding the phytochelatin synthase (AtPCS) and the iron regulated transporter (AtIRT1) from Arabidopsis thaliana. In rice paddy soil, addition of recombinant strain B3 carrying a plasmid with the MTL4, AtPCS and/or AtIRT1 genes significantly increased the accumulation of cadmium in roots and nodules of A. sinicus. Thus, this system uses the advantages of both plants and rhizobium. In particular, the system can easily transform engineered genes to the host plant through infection with a recombinant rhizobium.