PROBLEM TO BE SOLVED: To provide a device capable of detecting a state change of micro seaweed.SOLUTION: A determination device of a micro seaweed nutritional state includes: a flow cell 40 where a fluid containing micro seaweed passes through； an excitation light source 10 for irradiating the flow cell 40 with excitation light； a fluorescence detector 102 for detecting self-fluorescence generated by a chloroplast of micro seaweed to which excitation light is radiated； a scattered light detector 105 for detecting scattered light generated by micro seaweed to which excitation light is radiated； a ratio calculation section 301 for calculating a ratio of self-fluorescence intensity to scattered light intensity； a histogram generation section 302 for generating a histogram of the ratio； and a nutritional state determination section 303 for determining a micro seaweed nutritional state on the basis of a shape of a histogram.SELECTED DRAWING: Figure 1COPYRIGHT: (C)2020,JPO&INPIT【課題】微細藻類の状態変化を検出可能な装置を提供する。【解決手段】微細藻類を含む流体が流されるフローセル４０と、フローセル４０に励起光を照射する励起光光源１０と、励起光を照射された微細藻類の葉緑体で生じた自家蛍光を検出する蛍光検出器１０２と、励起光を照射された微細藻類で生じた散乱光を検出する散乱光検出器１０５と、自家蛍光の強度と、散乱光の強度と、の比を算出する比算出部３０１と、比のヒストグラムを生成するヒストグラム生成部３０２と、ヒストグラムの形状に基づき、微細藻類の栄養状態を判定する栄養状態判定部３０３と、を備える微細藻類の栄養状態の判定装置。【選択図】図１
