Light is one of the most important environmental factors affecting the growth and reproduction of algae. In this study, the effect of various LED colors on the productivity, chlorophyll (Chl-a, Chl-b, and total Chl), protein, and carbohydrate content of Isochrysis zhanjiangensis in indoor culture was investigated. Microalgae monocultures were cultivated under five different colors (red, green, blue, yellow, and white) for twenty-one days. The microalgae cultured under red light exhibited a higher specific growth rate (0.4431 ± 0.0055 µ day⁻¹), and under white light a higher productivity (0.0728 ± 0.0013 g L⁻¹ day⁻¹). The poorest performance was observed under yellow and green lights. Interestingly, green light exhibited the highest levels of chlorophylls (Chl-a, 1.473 ± 0.037 mg L⁻¹; Chl-b, 1.504 ± 0.001 mg L⁻¹; total Chl, 2.827 ± 0.083 mg L⁻¹). The highest protein content was observed under the white light (524.1935 ± 6.5846 mg L⁻¹), whereas the carbohydrate content was remarkably high under the blue light (24.4697 ± 0.0206 mg L⁻¹). This study is important in terms of the selection of light at the appropriate color (wavelength) to increase the content of organic compounds desired to be obtained indoors with the potential for commercially produced cultures.

The escalating impact of human activities has led to the accumulation of microplastics (MPs) and heavy metals in marine environments, posing serious threats to marine ecosystems. As essential components of oceanic ecosystems, large seaweeds such as Caulerpa lentillifera play a crucial role in maintaining ecological balance. This study investigated the effects of MPs and cadmium (Cd) on the growth, physiology, biochemistry, and Cd accumulation in C. lentillifera while elucidating the underlying molecular regulatory mechanisms. The results demonstrated that exposure to MPs alone significantly promoted the growth. In contrast, exposure to Cd either alone or in combination with MPs significantly suppressed growth by reducing stem and stolon length, bud count, weight gain, and specific growth rates. Combined exposure to MPs and Cd exhibited the most pronounced inhibitory effect on growth. MPs had negligible impact while Cd exposure either alone or combined with MPs impaired antioxidant defenses and exacerbated oxidative damage; with combined exposure being the most detrimental. Analysis of Cd content revealed that MPs significantly increased Cd accumulation in algae intensifying its toxic effects. Gene expression analysis revealed that Cd exposure down-regulated key genes involved in photosynthesis, impairing both photosynthetic efficiency and energy conversion. The combined exposure of MPs and Cd further exacerbated these effects. In contrast, MPs alone activated the ribosome pathway, supporting ribosomal stability and protein synthesis. Additionally, both Cd exposure alone or in combination with MPs significantly reduced chlorophyll B and soluble sugar content, negatively impacting photosynthesis and nutrient accumulation. In summary, low concentrations of MPs promoted C. lentillifera growth, but the presence of Cd hindered it by disrupting photosynthesis and antioxidant mechanisms. Furthermore, the coexistence of MPs intensified the toxic effects of Cd. These findings enhance our understanding of how both MPs and Cd impact large seaweed ecosystems and provide crucial insights for assessing their ecological risks.

In this study, the flavor compounds of ivory shell (Babylonia areolata) and their changes caused by ammonia and salinity stresses were studied. Ammonia stress improved the contents of free amino acids (FAAs), 5′-adenosine monophosphate (AMP), citric acid, and some mineral ions such as Na⁺, PO₄³⁻, and Cl⁻. The FAA contents decreased with increasing salinity, while the opposite results were observed in most inorganic ions (e.g., K⁺, Na⁺, Mg²⁺, Mn²⁺, PO₄³⁻, and Cl⁻). Hyposaline and hypersaline stresses increased the AMP and citric acid contents compared to the control group. The equivalent umami concentration (EUC) values were 3.53–5.14 g monosodium glutamate (MSG)/100 g of wet weight, and the differences in EUC values among treatments were mainly caused by AMP. Hexanal, butanoic acid, and 4-(dimethylamino)-3-hydroxy- and (E, E)-3,5-octadien-2-one were the top three volatile compounds, and their profiles were significantly affected when ivory shells were cultured under different ammonia and salinity conditions.