Chen B J, Hirt W, Lim H C, Tsao G T
Appl Environ Microbiol. 1977 Feb;33(2):269-74. doi: 10.1128/aem.33.2.269-274.1977.
A methylomonad culture was isolated from pond water and examined as a potential source of single-cell protein. A medium containing magnesium sulfate, ammonium hydroxide, sodium phosphate, tap water, and methanol supported the growth of the isolate. Optimal growth conditions in batch cultures for the organism were: temperature, 30 to 33 degrees C; pH 7.1; and phosphate concentration, 0.015 M. The minimum doubling time obtained was 1.6 h. The specific growth rate in batch culture was dependent on the methanol concentration, reaching a maximum around 0.2% (wt/vol). Growth inhibition was apparent above 0.3% (wt/vol), and growth was completely inhibited above 4.6% (wt/vol) methanol. Although the inhibitory effect of formaldehyde on the specific growth rate was much greater than that of formate, the organism utilized formaldehyde, but not formate, as a sole carbon and energy source in batch cultures. The isolate was identified primarily by its inability to utilize any carbon source other than methanol and formaldehyde for growth. Although it is capable of rapid growth on methanol, the organism showed a very weak catalase activity. The amino acid content of the cells compared favorably with the reference levels for the essential amino acids specific by the Food and Agricultural Organization of the United Nations.
从池塘水中分离出一种甲基单胞菌培养物，并将其作为单细胞蛋白的潜在来源进行检测。一种含有硫酸镁、氢氧化铵、磷酸钠、自来水和甲醇的培养基支持该分离物的生长。该生物体在分批培养中的最佳生长条件为：温度30至33摄氏度；pH值7.1；磷酸盐浓度0.015M。获得的最短倍增时间为1.6小时。分批培养中的比生长速率取决于甲醇浓度，在约0.2%（重量/体积）时达到最大值。在0.3%（重量/体积）以上明显出现生长抑制，在甲醇浓度高于4.6%（重量/体积）时生长完全受到抑制。虽然甲醛对比生长速率的抑制作用远大于甲酸，但该生物体在分批培养中利用甲醛作为唯一的碳源和能源，而不利用甲酸。该分离物主要通过其无法利用甲醇和甲醛以外的任何碳源进行生长来鉴定。虽然该生物体能够在甲醇上快速生长，但其过氧化氢酶活性非常弱。细胞的氨基酸含量与联合国粮食及农业组织规定的必需氨基酸参考水平相比具有优势。
