Microalgae produce a variety of high-value bioproducts, such as neutral lipids, polyunsaturated fatty acids, fucoxanthin, astaxanthin, and other pigments. Production studies typically quantify biomass as dry mass or estimate growth based on cell density, alongside biochemical metrics like fatty acid profiles and pigment contents. However, these bulk measurements do not reveal which coexisting life-cycle stages or physiological states were responsible for observed changes. This review offers a structured synthesis of evidence related to life-cycle stages, physiological states, and population-level events that impact target compound allocation and overall process performance. The evidence was analyzed based on perturbation, observable cell state, image-derived feature groups, biochemical endpoints, process outcomes, and validation strength. Specific emphasis was placed on Haematococcus, Chlamydomonas, and Tisochrysis/Isochrysis, as these taxa have available stage-resolved evidence or validation from single-cell to bulk assessments. Cross-study comparisons indicate that similar bulk biochemical responses can emerge from different population state compositions, while seemingly similar phenotypes can yield varying process outcomes. For example, a selfsettling state of Tisochrysis combined harvestability with productivity in fucoxanthin and docosahexaenoic acid, whereas non-motile aggregated states of Haematococcus indicated stress adaptation, storage allocation, and trade-offs with rapid proliferation. These differing outcomes are attributed to factors such as state origin, reversibility, growth costs, target compound allocation, and harvest benefits, rather than aggregation alone. Imagederived variables were categorized into morphological, fluorescence, and populationevent indicators. While these indicators facilitate state tracking, they do not correspond directly to biological states and require validation through methods such as time-series microscopy, gas chromatography or lipidomics, high-performance liquid chromatography or mass spectrometry, pulse-amplitude-modulated fluorometry, and independent cell counts. This evidence-based framework connects cell state interpretation to strain screening, stress diagnosis, harvest timing, scale-up assessment, and bioproduct quality control.

Abstract
1. 서 론
2. 문헌 범위와 비교 종합 방법
3. 바이오매스·생화학 지표와 생활사해석의 차이
4. 생활사 및 세포상태 판독을 위한관측 지표와 검증 원리
5. 생활사 기반 세포군 상태 구조의 정의와 범위
    5.1. 생활사 단계, 생리상태 및 집단사건의 구분
    5.2. 다중 지표 조합을 통한 상태 관측과 문헌 간 비교
    5.3. 영상 기반 상태 분류의 역할과 적용 범위
6. 생활사 기반 유용물질 생산 연구의 비교 종합
    6.1. 성장 단계·세포주기와 지방산·중성지질 축적
    6.2. Tisochrysis/Isochrysis : 생산성·자가침강·세포군 구조의 통합
    6.3. Haematococcus : 생활사 전환과아스타잔틴 생산의 상태 의존성
    6.4. 영양염 스트레스: 축적 촉진과 공정 실패의 분기
    6.5. 응집, 자가침강 및 EPS: 수확 이점과스트레스 비용의 조건부 균형
7. 영상 기반 자동분류의 방법론과 발전 방향
8. 공정 적용의 한계와 검증 전략
9. 결 론
적 요
CRediT authorship contribution statement
Declaration of Competing Interest
사 사
Declaration of Generative AI and AI-assistedTechnologies Use
REFERENCES

• 정남현(고려대학교 생명과학대학 융합생명공학과) | Namhyun Chung (Department of Biotechnology, College of Life Sciences and Biotechnology, Korea University, Seoul 02841, Republic of Korea)
• 강성모(한국생명공학연구원 생물자원센터 (KCTC), 고려대학교 생명과학대학 융합생명공학과) | Sungmo Kang (Biological Resource Center/Korean Collection for Type Cultures (KCTC), Korea Research Institute of Bioscience and Biotechnology, Jeongeup 56212, Republic of Korea, Department of Biotechnology, College of Life Sciences and Biotechnology, Korea University, Seoul 02841, Republic of Korea)
• 김기현(한국생명공학연구원 생물자원센터 (KCTC)) | Ki-Hyun Kim (Biological Resource Center/Korean Collection for Type Cultures (KCTC), Korea Research Institute of Bioscience and Biotechnology, Jeongeup 56212, Republic of Korea)
• 이준(한국생명공학연구원 생물자원센터 (KCTC), 과학기술연합대학원대학교 (UST) 바이오소재공학과) | Zhun Li (Biological Resource Center/Korean Collection for Type Cultures (KCTC), Korea Research Institute of Bioscience and Biotechnology, Jeongeup 56212, Republic of Korea, Department of Bioresource and Environmental Engineering, University of Science and Technology (UST), Daejeon 34113, Republic of Korea) Corresponding author