摘 要随着生物工程技术的进步， 我国现代发酵工业进入了一个快速发展的时

摘 要
随着生物工程技术的进步， 我国现代发酵工业进入了一个快速发展的时期，成为我国国民经济新的增长点。发酵过程控制是提高发酵性能的重要手段。经过最近几十年的努力，光学传感器，化学传感器和生物传感器（取决于检测原理）的发展为高效的生物过程监控策略的形成提供了基础。发酵尾气中氧气和二氧化碳浓度的变化可以反映发酵过程细胞代谢和物质的变化情况，能够体现出发酵过程相关的重要信息。因此尾气中氧气和二氧化碳成为主要检测项目。
为了对发酵过程产生的尾气进行有效的检测，分析尾气中氧气和二氧化碳的含量，计算获得呼吸代谢参数RQ，从而实现对发酵过程的有效控制，节约能源和发酵成本，提高发酵效率，本文设计了一种在线尾气分析仪。
本文主要从硬件设计和软件设计两方面完成对在线尾气分析仪的设计，将设计好的尾气分析仪制成工程样机应用于酿酒酵母发酵生产GSH过程控制，期望达到同时实现发酵尾气采集和过程控制的目的。本论文主要包括以下几个方面：
(1)系统硬件设计。从核心控制器和传感器的选型到系统电路、硬件之间的连接完成了系统硬件电路设计。采用Arduino mega2560单片机作为核心控制器，荧光学氧气传感器和红外二氧化碳传感器作为检测元件，以UART通信协议连接控制器和传感器，大大简化了系统硬件电路。反馈控制执行模块采用兰格蠕动泵，通过蠕动泵外控模块实现对蠕动泵的控制。
（2）系统软件设计。下位机程序通过类C语言对串口通信、数据采集、传感器校正、反馈控制等功能模块进行编程，上位机软件利用LabVIEW开发环境编写，采用VISA函数实现对下位机的通信，实现了数据采集与处理、实时显示与存储在内的多个模块的功能，界面直观，运行可靠。整个系统通过软硬件综合调试运行良好，对比市售尾气分析仪结果显示，本系统数据测量准确、可靠，能长期稳定运行，达到了预期目标。
（3）呼吸商(RQ)反馈控制酿酒酵母发酵法生产GSH过程。首先考察了摇瓶发酵、分批发酵、基于指数速率和恒速流加的补料分批发酵这三种发酵方式对酵母细胞生长和GSH合成的影响，发现基于指数速率和恒速流加的补料分批发酵方式细胞密度和GSH合成量较高，发酵培养72小时后细胞干重达到78.22 g/L，GSH产量为1798.48 mg/L。然后将尾气分析仪应用于GSH发酵过程中，采用RQ反馈控制葡萄糖补料速率，经Arduino PID控制将RQ维持在设定值左右。对比不同RQ条件下GSH产量和细胞密度，发现当RQ控制在0.82时GSH和细胞生物量最高，分别达到1.61 g/L 和55.12 g/L（DCW）。添加前体氨基酸能进一步提高细胞GSH产量，在RQ反馈控制发酵过程中添加前体氨基酸，与未添加前体氨基酸相比产量明显提高，GSH总产量达2.47 g/L，提高53.42%，细胞干重达62.18 g/L，提高 12.81%，胞内GSH含量提高了32.27%。
关键词：发酵尾气 RQ 谷胱甘肽 Arduino 反馈控制

結果 (中文) 3:

Abstract:
with biological engineering technology progress, our country modern fermentation industry has entered a rapid development period, has become a new growth point of national economy in our country. Fermentation process control is an important means to improve the fermentation performance. After the recent dozens of years, optical sensors, chemical sensors and biosensors (depending on the detection principle of) development provides the basis for the formation of biological process monitoring strategy effectively. Changes of oxygen and carbon dioxide concentration in tail gas can reflect changes in the fermentation process of cell metabolism and material, which can reflect the important information related to the fermentation process.Therefore in the tail gas of oxygen and carbon dioxide as the main test items.
to of gas produced during the fermentation process for effective detection, analysis of the content of oxygen and carbon dioxide in the exhaust gas, calculate the respiratory metabolism parameters of RQ, so as to realize the effective control of the fermentation process, save energy and improve the efficiency of fermentation, the fermentation cost, this paper designs an on-line gas analyzer. This paper mainly completes the design of online
exhaust gas analyzer from two aspects of hardware design and software design, exhaust gas analyzer designed into engineering prototype used in the fermentation of Saccharomyces cerevisiae GSH production process control,At the same time to achieve the desired fermentation tail gas collection and process control. The paper mainly includes the following aspects: (1) the design of system hardware. From the connection between controller and sensor selection to the system hardware circuit, completed the hardware circuit design. Using Arduino mega2560 microcontroller as the core controller, fluorescence, oxygen sensor and infrared carbon dioxide sensor as the detecting element, using UART communication protocol to connect the sensor and controller, which greatly simplifies the hardware circuit of the system. Feedback control execution module using Lange peristaltic pump, through the peristaltic pump control module to realize the control of the peristaltic pump.
(2) the design of system software. The lower computer program by C language programming of serial communication, data acquisition, sensor calibration, the feedback control module, host computer software is programmed with LabVIEW development environment, using VISA function to realize the communication of MCU, realizes the data acquisition and processing, real time display and storage module, function, intuitive interface, reliable operation. The entire system through software and hardware debugging results show that the exhaust gas analyzer is running well, the sale of comparison, the data measured by the system is accurate, reliable, long-term stable operation, to achieve the expected goal.
(3) the respiratory quotient (RQ) feedback control of Saccharomyces cerevisiae fermentation production of GSH. First examine the shake flask fermentation, batch fermentation, the exponential rate and a constant flow of feeding and batch fermentation of these three kinds of fermentation effects on growth and GSH synthesis of yeast cells were found based on the exponential rate, and a constant flow of the fed batch fermentation was higher cell density and GSH synthesis based on the fermentation, 72 hours later, cell dry weight to 78.22 g/L, GSH yield was 1798.48 mg/L. And then the exhaust gas analyzer was applied to GSH in the fermentation process, the RQ feedback control of glucose feeding rate, the Arduino PID control RQ maintained at the set value.Comparison of different RQ conditions, GSH production and cell density, found that when the RQ control in the 0.82 GSH and the cell biomass was the highest, reached 1.61 g/L and 55.12 g/L respectively (DCW). Adding the precursor amino acid can improve the cell yield of GSH, adding the precursor amino acids in the fermentation process control RQ feedback, compared with not adding the precursor amino acid yield was increased, GSH production reached 2.47 g/L, increased by 53.42%, dry cell weight 62.18 g/L, increased by 12.81%, the content of intracellular GSH was increased by 32.27%. Keywords:
fermentation tail gas RQ glutathione Arduino feedback control.