Abdullahi Zulaihat Hamza, Marselin Fasihah Natasha, Khaironizam Nur Izatul Aisyah, Fauzi Nur Fatihah Ahmad, Wan Maznah W O
School of Biological Sciences, Universiti Sains Malaysia, 11800, Penang, Malaysia.
School of Biological Sciences, Universiti Sains Malaysia, 11800, Penang, Malaysia; Centre for Marine and Coastal Studies (CEMACS), Universiti Sains Malaysia, 11800, Penang, Malaysia; River Engineering and Urban Drainage Centre (REDAC), Universiti Sains Malaysia, Seri Ampangan, 14300, Nibong Tebal, Penang, Malaysia.
Plant Physiol Biochem. 2023 Apr;197:107633. doi: 10.1016/j.plaphy.2023.03.010. Epub 2023 Mar 9.
As part of the lampenflora that inhabit limestone caves, microalgae play an important role in cave ecosystems but are understudied in tropical ecoregions. In the present study, the dominant eukaryotic and prokaryotic microalgae identified in lampenflora samples collected from Gua Tempurung, a cave in Malaysia, and growth stage-related microalgal attributes were determined. Stichococcus bacillaris, Synechococcus sp., and Trentepohlia aurea were selected and cultured in Bold's Basal Medium (S. bacillaris and T. aurea) or BG-11 medium (Synechococcus sp.) under laboratory conditions. The highest specific growth rate (0.72 ± 0.21 day) and dry weight (0.11 ± 0.04 mg L) were recorded in S. bacillaris in the early stationary phase. Trentepohlia aurea and Synechococcus sp. had the highest ash-free dry weight and total ash percentage (11.18 ± 4.64 mg L and 8.55% ± 6.73%, respectively) in the early stationary phase. Stichococcus bacillaris had the highest moisture content (84.26% ± 0.64%) in the exponential phase. Chlorophylls a and b were highest in the early stationary phase in T. aurea (0.706 ± 0.40 mg L and 1.094 ± 0.589 mg L, respectively). Carotenoid levels were highest in Synechococcus sp. in the early stationary stage (0.07 ± 0.02 mg L). Lipids were the major biochemical compound identified at the highest levels in Synechococcus sp. (67.87% ± 7.75%) in the early stationary phase, followed by protein recorded at the highest levels in T. aurea (57.99% ± 4.99%) in the early stationary phase. Carbohydrates were the compound identified least often with the highest recorded levels found in T. aurea (9.94% ± 0.49%) in the late stationary phase. Biomass, pigments, and biochemical accumulation varied at different growth stages in the studied microalgae, and this variation was species-specific. The present study provides a benchmark for the growth phases of aerophytic cave microalgae, which will be useful for determining their optimum harvest time and obtaining biochemical compounds of interest.
作为栖息在石灰岩洞穴中的洞穴植物群的一部分，微藻在洞穴生态系统中发挥着重要作用，但在热带生态区域却未得到充分研究。在本研究中，我们确定了从马来西亚的一个洞穴——黑风洞采集的洞穴植物群样本中占主导地位的真核和原核微藻，以及与生长阶段相关的微藻属性。选择了杆状裂丝藻、聚球藻属和金藻 Trentepohlia aurea，并在实验室条件下，将杆状裂丝藻和金藻 Trentepohlia aurea 培养在 Bold 基础培养基中，将聚球藻属培养在 BG - 11 培养基中。杆状裂丝藻在稳定期早期的比生长速率最高（0.72 ± 0.21 天⁻¹），干重最高（0.11 ± 0.04 mg L⁻¹）。金藻 Trentepohlia aurea 和聚球藻属在稳定期早期的无灰干重和总灰分百分比最高（分别为 11.18 ± 4.64 mg L⁻¹ 和 8.55% ± 6.73%）。杆状裂丝藻在指数期的水分含量最高（84.26% ± 0.64%）。金藻 Trentepohlia aurea 在稳定期早期的叶绿素 a 和 b 含量最高（分别为 0.706 ± 0.40 mg L⁻¹ 和 1.094 ± 0.589 mg L⁻¹）。聚球藻属在稳定期早期的类胡萝卜素水平最高（0.07 ± 0.02 mg L⁻¹）。脂质是在稳定期早期聚球藻属中鉴定出的含量最高的主要生化化合物（67.87% ± 7.75%），其次是蛋白质，在稳定期早期金藻 Trentepohlia aurea 中含量最高（57.99% ± 4.99%）。碳水化合物是在稳定期末期金藻 Trentepohlia aurea 中鉴定出的含量最高但出现频率最低的化合物（9.94% ± 0.49%）。在所研究的微藻中，生物量、色素和生化物质积累在不同生长阶段有所不同，且这种差异具有物种特异性。本研究为气生洞穴微藻的生长阶段提供了一个基准，这将有助于确定它们的最佳收获时间并获得感兴趣的生化化合物。
