A new marine strain of picoplanktonic algae, PMPFPPE4, was isolated from a mixed net-phytoplankton sample taken from the upper euphotic layer of the southeastern Adriatic Sea. Evaluation of the new strain included morphological investigation (by light and electron microscopy), phylogenetic analysis (utilizing plastid 16S rRNA and nuclear 18S rRNA genes), and physiological characterization (screening of pigment/lipid composition and capturing photosynthesis measurements). The new strain was proven to belong to the genus Picochlorum and the lipid composition revealed an unexpected accumulation of triacylglycerols, indicating an evolutionary adaptation for growth under unfavourable conditions. In addition, lipid remodelling in the exponential to stationary growth phase was characterized by an increased share of membrane-forming digalactosyldiacylglycerols and phosphatidylcholines. Maximum photosynthetic activity measured was at 30°C, but the most rapid increase of photosynthetic activity was at lower temperatures (15–20°C). Moreover, the thermotolerant strain did not exhibit photoinhibition below 40°C and survived a one-month cultivation period in complete darkness. The strain’s survival in low light and dark conditions suggests a potential shift from autotrophy to mixotrophy under unfavourable growth conditions. Thus, the unique physiological attributes represented by a high growth rate, thermotolerance, phototolerance and high triacylglycerol synthesis may render the strain highly attractive for biofuel production and growth in large outdoor systems.

从东南亚得里亚海上层的富营养层中提取的一个混合的浮游植物净海藻样品中分离出了一种新的微浮游藻类海洋菌株PMPFPPE4。对新菌株的评估包括形态学研究（通过光学和电子显微镜），系统发育分析（利用质体16S rRNA和核18S rRNA基因）和生理学表征（筛选色素/脂质成分并捕获光合作用测量值）。新菌株被证明是属于四氯青霉属。脂质组成显示出三酰甘油的意外积累，表明在不利条件下生长的进化适应性。另外，脂质向指数重生到静止生长期的重塑特征在于成膜的二半乳糖基二酰基甘油和磷脂酰胆碱的份额增加。测得的最大光合作用活性是在30°C时，但是在较低温度（15–20°C）下光合作用的增长最快。此外，该耐热菌株在40℃以下没有光抑制作用，并且在完全黑暗的条件下可以存活一个月。该菌株在弱光和黑暗条件下的存活率表明，在不利的生长条件下，该菌种可能会从自养变为混养。从而，