@article{oai:ir.kagoshima-u.ac.jp:00011031,
 author = {柏田, 研一 and 柿本, 大壱},
 issue = {2},
 journal = {鹿児島大学水産学部紀要=Memoirs of Faculty of Fisheries Kagoshima University},
 month = {2016-10-31},
 note = {We have as yet very little information as to the appearance of vitamins in natural water. This paper deals with the folic acid content in inland water. The folic
acid was determined by microbioassay method using Streptococcus faecalis R as the
test organism. The water was applied to determination after concentrated to one fifth of the initial volume under reduced pressure. The results obtained are as follows;
1) Folic acid was contained in the river water at Kagoshima City in the range of 0 to 260 mγ/l in January, and it was found that the content was abundant in the polluted water. (Table 1)
2) In the water of Lake Ikeda, no vertical fluctuation in folic acid content was
observed. And it was found that tha folic acid content of the lake water was not
less than that of the river water. (Table 2), 3) It was likely that in the river water the folic acid was contained mostly as
dissolved state, not as a cell constituent of organisms such as bacteria. (Table 3)
4) As shown in Table 4 and 5, folic acid content in the river water increased in
the early stage of storage, but it decreased gradually with the lapse of time. Striking fluctuation in folic acid content during storage was observed in the down stream water. (Table 5)
5) In the river water stored at a low temperature such as 5°C, the content of
folic acid increased more slowly as compared with the water which was stored at a
higher temperature such as 25°C. However, the folic acid reached to higher levels
under the former storage condition than under the latter. (Table 6), Streptococcus faecalis R を用うるバイオアッセイ法により陸水中の葉酸含量について研究し,次の事実を明らかにした。 1)鹿児島市内の4つの河の水につき1月に葉酸量を測定した結果,その含量は0ないし260mγ/lの範囲にあり,下水などの混入で汚れた水ほど含有量が多かった。 2)池田湖では葉酸の垂直分布を調べたが一定の傾向は認められなかった。12月の水では葉酸含量は24~104mγ/lであった。 3)河水中の葉酸は大部分Chamberlandの濾過器を通過するので,水中に溶解して存在することが判った。 4)河水を貯蔵すると葉酸は増加し,数日後に最高値に達した後次第に減少する。この葉酸量の増減は同一の河川については上流の水よりも下流の水の方が著しいので,河水中における葉酸量の消長には水中の細菌類の関与していることが推定される。 5)河水を低温(5°C)と高温(25°C)に貯蔵した場合における葉酸量の消長を比較すると,低温に貯蔵した場合の方が最高含量に達するのに長時間を要するが,葉酸含量の達する最高値は低温に貯蔵した場合の方が多い。},
 pages = {158--164},
 title = {天然水中の有機物に関する研究 I : 陸水の葉酸含量について},
 volume = {11},
 year = {}
}