A systematic review of the predatory contaminant Poterioochromonas in microalgal culture

Abstract

Contamination by zooplankton has to a certain extent limited the large-scale cultivation and industrial exploitation of microalgae. However, systematic research on these predators in microalgal culture is still lacking. The identification of zooplanktonic contaminants derived from microalgal cultures is a basis for conducting related studies. Moreover, knowledge of the ecological distribution of such predators is crucial for avoiding or reducing the risk of biological contamination in the management of large-scale microalgal cultures. Understanding the feeding behaviors of zooplanktonic contaminants contributes to the establishment of targeted prevention strategies and control methods. Early detection is essential to allow prevention and control measures to be implemented in a timely and effective way. Reducing the susceptibility of the cultured microalgae to predators through breeding strains selection, the potential of modern molecular methods, or a synthesis of these approaches will be indispensable to the management of zooplankton contamination. Furthermore, exploring the resource utilization of predators helps to understand this issue comprehensively and to turn hazard into wealth. The genus Poterioochromonas is a typical mixotrophic flagellate and has attracted increasing attention because of the dramatic damage it can inflict on a wide range of microalgal cultures, regardless of the culture system, season, or environment. This review explores our current understanding of the predator Poterioochromonas and the areas where further research is needed, which should stimulate reflection on what we still need to know about these predators from a microalgal culture perspective and how we can utilize them.

Botryococcus brauniireduces algal grazing losses toDaphniaandPoterioochromonasthrough both chemical and physical interference

“…We used Daphnia magna and Poterioochromonas malhamensis as our two taxonomically and functionally distinct grazer species, and Nannochloropsis limnetica as a small (< 4 µm diameter), fast-growing target alga for co-culture with B. braunii. Daphnia was chosen as a representative large-bodied (length < 1 mm as juvenile; 1-5 mm as adult), filter-feeding arthropod zooplankton grazer with a larger prey size, while the golden alga Poterioochromonas was chosen as a representative small-celled (< 10 µm diameter) flagellate with a smaller prey size that consumes cells via phagocytosis; both are common worldwide and are capable of strong top-down control of algal biomass [2,17]. We experimentally tested the following hypotheses: H1) B. braunii reduces algal biomass losses due to grazing via a combination of chemical and physical interference; and H2) B. braunii does not chemically inhibit Nannochloropsis growth.…”

Transcriptional profile reveals the physiological responses to prey availability in the mixotrophic chrysophyte Poterioochromonas malhamensis

“…Poterioochromonas malhamensis is a common mixotrophic flagellate that is widely distributed in aquatic ecosystems ( Ma et al, 2023 ). The nutritional characteristics and relationships among different nutritional modes of P. malhamensis have been widely studied ( Ma et al, 2023 ).…”

“…Poterioochromonas malhamensis is a common mixotrophic flagellate that is widely distributed in aquatic ecosystems ( Ma et al, 2023 ). The nutritional characteristics and relationships among different nutritional modes of P. malhamensis have been widely studied ( Ma et al, 2023 ). It is considered to be a predominately heterotrophic mixotroph as photosynthesis contributes less than 7% of its total carbon budget in the simultaneous presence of abundant organics and light ( Sanders et al, 1990 ).…”

“…The protein and amino acid content of P. malhamensis will decrease when transforming from autotrophy to heterotrophy, while the carbohydrate and fatty acid contents show opposite trends ( Ma et al, 2022b ). Despite these findings, thus far, the molecular responses of P. malhamensis to different nutritional modes have rarely been studied ( Ma et al, 2023 ). However, the rapid development of transcriptomic analysis has provided a high throughput approach that can be used to better understand the physiological and molecular responses of mixotrophic flagellates to different nutritional modes, or even to potentially identify the genes connected with specific nutritional strategies ( Caron et al, 2017 ).…”